JP4743452B2 - Polymer compound, resist protective film material, and pattern forming method - Google Patents

Description

  The present invention is a photolithography for fine processing in a manufacturing process of a semiconductor device or the like, for example, an exposure liquid by using a ArF excimer laser with a wavelength of 193 nm as a light source and inserting a liquid (for example, water) between a projection lens and a substrate. The present invention relates to a resist protective film material for forming a protective film on a resist film in order to protect the resist material to be used in immersion photolithography, a base polymer thereof, and a pattern forming method using these materials.

In recent years, along with higher integration and higher speed of LSI, pattern rule miniaturization is progressing rapidly. The background of this is the shortening of the wavelength of the exposure light source. For example, a 64 Mbit DRAM (dynamic size of 0.25 μm or less) DRAM (dynamic Random access memory) is now available for mass production. Furthermore, in order to realize DRAM manufacturing with an integration degree of 256M and 1G or more, lithography using an ArF excimer laser (193 nm) has been studied in earnest, and 65 nm by combining with a high NA lens (NA ≧ 0.9). Node devices are being studied. Postponed its Although the use of F ₂ laser having a wavelength of 157nm to device fabrication of the next 45nm node is a candidate. In addition to the disadvantage in cost, is applied by a number of the problems typified by poor performance of the resist It was done. Then, ArF immersion lithography has been proposed as an alternative to F ₂ lithography, and is currently being developed for its early introduction (Non-patent Document 1: Proc. SPIE. Vol. 4690, xxix (2002). )reference).

  In ArF immersion lithography, water is impregnated between a projection lens and a wafer, and ArF excimer laser is irradiated through the water. Since the refractive index of water at 193 nm is 1.44, it is possible to form a pattern using a lens having an NA of 1.0 or more, and 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 suggested by a combination of a lens having an NA of 1.2 or more and a strong super-resolution technique (Non-Patent Document 2: Proc. SPIE. Vol. 5040). P724 (2003)).

  However, when exposure is performed in the presence of water on the resist film, the acid generated in the resist film and some of the basic compounds added to the resist material are eluted into the aqueous layer (leaching). As a result, there is a possibility that a pattern change or pattern collapse occurs. It has also been pointed out that defects may occur when a small amount of water droplets remaining on the resist film penetrates into the resist film.

  In order to improve these drawbacks, ArF immersion lithography has been proposed in which a protective film is provided between the resist film and water to suppress elution of the resist components and water permeation into the resist film (non-patent document). 3: 2nd Immersion Work Shop: See Resist and Cover Material Investigation for Immersion Lithography (2003)).

  As a protective film material for a photoresist film, an ARCOR method (antireflective coating on resist; for example, Patent Documents 1 to 3: Japanese Patent Laid-Open Nos. 62-62520, 62-62521, and 60-38821). Low-refractive-index materials such as perfluoroalkyl polyethers and perfluoroalkylamines typified by the publication are known. However, these fluorine-containing compounds have low compatibility with organic substances, and use of a chlorofluorocarbon-based solvent for coating / peeling of the protective film has great disadvantages in terms of environment and cost.

  As other resist protective film materials, application of water-soluble or alkali-soluble materials has been studied (Patent Documents 4 and 5: JP-A-6-273926, Patent 2803549, Non-Patent Document 4). : J. Photopolymer.Sci. And Technol.Vol.18, No. 5, p615 (2005)). Among these, since the alkali-soluble resist protective film material can be peeled off with an alkali developer, it is not necessary to add a peeling device, and the cost advantage is great. Therefore, for example, water-insoluble resist protective film materials using a resin having an alkali-soluble group such as a fluorine-containing alcohol, a carboxyl group, or a sulfo group in the side chain are being developed (Patent Documents 6 to 10: International publication). No. 2005/42453 pamphlet, WO 2005/69676 pamphlet, JP 2005-264131 A, JP 2006-133716 A, JP 2006-91798 A).

  The performance required for resist protective film materials includes water repellency and water slidability as well as the ability to prevent the acid and basic compounds generated in the photoresist film from eluting into water and the ability to prevent water from penetrating into the resist film. Performance is also required. Among these, it has been reported that introduction of fluorine into the resin is effective for improving water repellency, and formation of a microdomain structure by a combination of different water repellant groups is effective for improving water slidability ( For example, see Non-Patent Documents 5 and 6: XXIV FATIPEC Congress Book, Vol. B, p15 (1997), Progress in Organic Coatings, 31, p97 (1997)).

  An example of a polymer exhibiting high water slidability and water repellency is a fluorine-containing ring-closing polymer having a hexafluoroalcohol group in the side chain. This polymer can be protected by protecting the hydroxyl group of the side chain with an acid labile group. It has been reported that the water performance is further improved (see Non-Patent Document 7: Proc. SPIE. Vol. 6519, p651905 (2007)).

  The introduction of fluorine into the resin not only increases the water repellency of the resin, but is also effective in improving the water sliding performance such as the falling angle and receding contact angle. However, if fluorine is introduced excessively, surface contact after alkali development The corner becomes high. Recently, a defect called blob that occurs on the surface of the resist film after development (especially in the unexposed part) has been regarded as a problem, but it has been found that this defect tends to occur more frequently with a highly water-repellent resist film. ing. Therefore, if fluorine is introduced excessively to increase the water repellency and water slidability of the resin, blob defects are likely to occur.

  The cause of blob defects is thought to be water droplets remaining on the resist film surface after development. The internal energy of the water droplet on the resist film rises in the course of drying by spin drying, and the energy becomes maximum when the water droplet completely leaves the surface. Then, at the same time as the water droplet leaves the resist film surface, the resist film surface is damaged by the energy, and this is observed as a blob defect.

  Since the internal energy of water droplets on the resist film is higher at higher water-repellent surfaces, application of a highly water-repellent protective film increases the contact angle between the resist film and the protective film, resulting in blob defects. It becomes easy to do. Therefore, in order to suppress the occurrence of blob defects, it is necessary to reduce the surface contact angle after development in order to reduce the internal energy of the water droplets.

  In order to reduce the surface contact angle after development, it is conceivable to apply a highly hydrophilic resist protective film. However, with such a protective film, the receding contact angle decreases and high-speed scanning becomes impossible. Due to the watermark defect. Further, a resist protective film having a carboxyl group or a sulfo group has been proposed (see Patent Document 10: Japanese Patent Application Laid-Open No. 2006-91798). However, since the carboxyl group and the sulfo group are also highly hydrophilic, they have water repellency and water slidability. Will fall.

  Therefore, a protective film is proposed in which a polymer having a sulfo group is blended with a polymer having a highly water-repellent hexafluoroalcohol group to align the polymer having a hexafluoroalcohol group on the surface of the protective film and the polymer having a sulfo group on the resist surface. (See Non-Patent Document 8: 4th Immersion Symposium RE-04 New Materials for surface energy control of 193 nm photoetists, Dan sander et al.). When such a protective film is used, blob defects can be reduced, but the sulfo group is bonded to the amine component in the resist and the amine component near the resist surface is deficient, resulting in a reduction in the resist pattern film thickness after development. Therefore, it is desired to develop a protective film that suppresses film loss in order to obtain a rectangular pattern and increases the hydrophilicity of the resist surface after development in order to prevent blob defects.

  The materials described above are required not only for ArF immersion lithography but also for electron beam lithography. When performing electron beam exposure for mask drawing or the like, it has been pointed out that the sensitivity of the resist fluctuates due to evaporation of vinyl ether generated by deprotection of the acid and acetal protecting group generated during drawing (for example, Patent Document 11: see JP-A-2002-99090). Therefore, a method has been proposed in which a resist protective film material is applied to form a barrier film on the resist upper layer to suppress sensitivity fluctuation.

Proc. SPIE. Vol. 4690, xxix (2002) Proc. SPIE. Vol. 5040, p724 (2003) 2nd Immersion Work Shop: Resist and Cover Material Investigation for Immersion Lithography (2003) J. et al. Photopolymer. Sci. and Technol. Vol. 18, no. 5, p615 (2005) XXIV FATIPEC Congress Book, Vol. B, p15 (1997) Progress in Organic Coatings, 31, p97 (1997) Proc. SPIE. Vol. 6519, p651905 (2007) 4th Immersion Symposium RE-04 New Materials for surface energy control of 193 nm photosorists, Dan sander et. al. JP-A-62-62520 JP-A-62-62521 JP 60-38821 A JP-A-6-273926 Japanese Patent No. 2803549 International Publication No. 2005/42453 Pamphlet International Publication No. 2005/69676 Pamphlet JP 2005-264131 A JP 2006-133716 A JP 2006-91798 A JP 2002-99090 A

  The present invention has been made in view of the above problems, and is a resist protective film that is effective for immersion lithography with excellent water repellency and water slidability, less development defects, and good resist pattern shape after development. It is an object of the present invention to provide a material, a polymer compound serving as a base polymer thereof, and a pattern forming method using the material.

  As a result of intensive studies to achieve the above object, the present inventors have developed a novel polymer compound having a cyclic acetal structure represented by the following general formulas (1) to (3) by a method described later. It has been found that it has excellent water repellency and water slidability as a base polymer for a protective film material, and the performance can be adjusted by selecting a structure. In addition, the present inventors have found that a resist protective film material with few development defects and excellent pattern shape can be obtained by blending the above-described novel polymer compound with a polymer containing a sulfonic acid amine salt in a repeating unit. It has been completed. The base polymer used in the present invention has excellent transparency with respect to radiation having a wavelength of 200 nm or less, and adjustment of various performances such as water repellency, water slidability, fat solubility, acid decomposability, and hydrolyzability by selection of the resin structure. Can be produced from raw materials that are easy to obtain and handle.

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｘは一般式（Ｘ−１）〜（Ｘ−３）で表されるいずれかの構造を表す。一般式（Ｘ−１）の中でＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。Ｒ⁴は炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、メチレン基の一部が酸素原子又はカルボニル基で置換されていてもよい。一般式（Ｘ−１）はＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bのいずれかを介して繰り返し単位（１）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｘ−２）の中でＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｘ−２）はＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bのいずれかを介して繰り返し単位（１）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｘ−３）の中でＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｘ−３）はＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを介して繰り返し単位（１）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。なお、Ｒ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3b、Ｒ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7b、Ｒ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを連結基として繰り返し単位（１）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する場合、当該連結基は、上記定義において、その有機基に含まれる水素原子が１個脱離し、この脱離箇所が結合手とされた基である。）
請求項２：
下記一般式（２）で表される繰り返し単位を有することを特徴とする、重量平均分子量が１，０００〜５００，０００の範囲である高分子化合物。

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｙは一般式（Ｙ−１）〜（Ｙ−３）で表されるいずれかの構造を表す。一般式（Ｙ−１）の中でＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｙ−１）はＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bのいずれかを介して繰り返し単位（２）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｙ−２）の中でＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｙ−２）はＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bのいずれかを介して繰り返し単位（２）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｙ−３）の中でＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｙ−３）はＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを介して繰り返し単位（２）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。Ｒ¹⁰は炭素数１〜１９の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、また、メチレン基の一部が酸素原子、又はカルボニル基で置換されていてもよい。なお、Ｒ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3b、Ｒ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7b、Ｒ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを連結基として繰り返し単位（２）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する場合、当該連結基は、上記定義において、その有機基に含まれる水素原子が１個脱離し、この脱離箇所が結合手とされた基である。）
請求項３：
下記一般式（３）で表される繰り返し単位を有することを特徴とする、重量平均分子量が１，０００〜５００，０００の範囲である高分子化合物。

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｚは一般式（Ｚ−１）〜（Ｚ−３）で表されるいずれかの構造を表す。一般式（Ｚ−１）の中でＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｚ−１）はＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bのいずれかを介して繰り返し単位（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｚ−２）の中でＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｚ−２）はＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bのいずれかを介して繰り返し単位（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｚ−３）の中でＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｚ−３）はＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを介して繰り返し単位（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。Ｒ¹¹は水素原子又は炭素数１〜１８の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、また、メチレン基の一部が酸素原子、又はカルボニル基で置換されていてもよい。Ｒ¹²は炭素数１〜１９の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、また、メチレン基の一部が酸素原子、又はカルボニル基で置換されていてもよい。Ｒ¹¹とＲ¹²は結合してこれらが結合する炭素原子及び酸素原子と共に環状構造を形成してもよい。なお、Ｒ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3b、Ｒ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7b、Ｒ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを連結基として繰り返し単位（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する場合、当該連結基は、上記定義において、その有機基に含まれる水素原子が１個脱離し、この脱離箇所が結合手とされた基である。）
請求項４：
更に、下記一般式（４ａ）〜（４ｆ）で表される繰り返し単位のうちの１つ又は２つ以上を含むことを特徴とする請求項１乃至３のいずれか１項記載の高分子化合物。

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｒ^13a及びＲ^13bは水素原子、又は炭素数１〜１５の直鎖状、分岐状又は環状のアルキル基であり、Ｒ^13aとＲ^13bは互いに結合してこれらが結合する炭素原子と共に環を形成することもできる。Ｒ¹⁴は水素原子、炭素数１〜１５の直鎖状、分岐状又は環状のアルキル基又はフッ素化アルキル基、又は酸不安定基である。Ｒ¹⁵は炭素数１〜１５の直鎖状、分岐状又は環状のフッ素化アルキル基である。Ｒ¹⁶は酸不安定基である。）
請求項５：
下記一般式（１）で表される繰り返し単位を有する高分子化合物を含むことを特徴とするレジスト保護膜材料。

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｘは一般式（Ｘ−１）〜（Ｘ−３）で表されるいずれかの構造を表す。一般式（Ｘ−１）の中でＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。Ｒ⁴は炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、メチレン基の一部が酸素原子又はカルボニル基で置換されていてもよい。一般式（Ｘ−１）はＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bのいずれかを介して繰り返し単位（１）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｘ−２）の中でＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｘ−２）はＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bのいずれかを介して繰り返し単位（１）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｘ−３）の中でＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｘ−３）はＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを介して繰り返し単位（１）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。なお、Ｒ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3b、Ｒ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7b、Ｒ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを連結基として繰り返し単位（１）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する場合、当該連結基は、上記定義において、その有機基に含まれる水素原子が１個脱離し、この脱離箇所が結合手とされた基である。）
請求項６：
下記一般式（２）で表される繰り返し単位を有する高分子化合物を含むことを特徴とするレジスト保護膜材料。

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｙは一般式（Ｙ−１）〜（Ｙ−３）で表されるいずれかの構造を表す。一般式（Ｙ−１）の中でＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｙ−１）はＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bのいずれかを介して繰り返し単位（２）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｙ−２）の中でＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｙ−２）はＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bのいずれかを介して繰り返し単位（２）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｙ−３）の中でＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｙ−３）はＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを介して繰り返し単位（２）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。Ｒ¹⁰は炭素数１〜１９の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、また、メチレン基の一部が酸素原子、又はカルボニル基で置換されていてもよい。なお、Ｒ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3b、Ｒ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7b、Ｒ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを連結基として繰り返し単位（２）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する場合、当該連結基は、上記定義において、その有機基に含まれる水素原子が１個脱離し、この脱離箇所が結合手とされた基である。）
請求項７：
下記一般式（３）で表される繰り返し単位を有する高分子化合物を含むことを特徴とするレジスト保護膜材料。

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｚは一般式（Ｚ−１）〜（Ｚ−３）で表されるいずれかの構造を表す。一般式（Ｚ−１）の中でＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｚ−１）はＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bのいずれかを介して繰り返し単位（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｚ−２）の中でＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｚ−２）はＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bのいずれかを介して繰り返し単位（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｚ−３）の中でＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｚ−３）はＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを介して繰り返し単位（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。Ｒ¹¹は水素原子又は炭素数１〜１８の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、また、メチレン基の一部が酸素原子、又はカルボニル基で置換されていてもよい。Ｒ¹²は炭素数１〜１９の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、また、メチレン基の一部が酸素原子、又はカルボニル基で置換されていてもよい。Ｒ¹¹とＲ¹²は結合してこれらが結合する炭素原子及び酸素原子と共に環状構造を形成してもよい。なお、Ｒ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3b、Ｒ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7b、Ｒ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを連結基として繰り返し単位（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する場合、当該連結基は、上記定義において、その有機基に含まれる水素原子が１個脱離し、この脱離箇所が結合手とされた基である。）
請求項８：
更に、下記一般式（４ａ）〜（４ｆ）で表される繰り返し単位のうちの１つ又は２つ以上を有する高分子化合物を含むことを特徴とする請求項５乃至７のいずれか１項記載のレジスト保護膜材料。

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｒ^13a及びＲ^13bは水素原子、又は炭素数１〜１５の直鎖状、分岐状又は環状のアルキル基であり、Ｒ^13aとＲ^13bは互いに結合してこれらが結合する炭素原子と共に環を形成することもできる。Ｒ¹⁴は水素原子、炭素数１〜１５の直鎖状、分岐状又は環状のアルキル基又はフッ素化アルキル基、又は酸不安定基である。Ｒ¹⁵は炭素数１〜１５の直鎖状、分岐状又は環状のフッ素化アルキル基である。Ｒ¹⁶は酸不安定基である。）
請求項９：
下記一般式（５）又は（６）で表される繰り返し単位を有する高分子化合物を含むことを特徴とする請求項５乃至８のいずれか１項記載のレジスト保護膜材料。

（式中、Ｒ^31a及びＲ^31bは水素原子又はメチル基である。Ｒ³²は単結合、炭素数１〜４のアルキレン基、フェニレン基、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−ＮＨ−のいずれかである。Ｒ³³は単結合、炭素数１〜８の直鎖状、分岐状又は環状のアルキレン基のいずれかである。Ｒ^34a〜Ｒ^34d及びＲ^36a〜Ｒ^36cはそれぞれ独立に水素原子、炭素数１〜１２の直鎖状、分岐状又は環状のアルキル基、アルケニル基、オキソアルキル基又はオキソアルケニル基、炭素数６〜２０のアリール基、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のいずれかを示し、これらのうち水素原子の一部又は全部がアルコキシ基によって置換されていてもよく、Ｒ^34a〜Ｒ^34d及びＲ^36a〜Ｒ^36cの中に窒素原子、エーテル基、エステル基、ヒドロキシ基、又はカルボキシル基を含んでいてもよい。Ｒ^34a〜Ｒ^34d及びＲ^36a〜Ｒ^36cのうち２個は互いに結合してこれらが結合する窒素原子と共に環を形成することができ、その場合それぞれ独立に炭素数３〜１５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。Ｒ³⁵は炭素数１〜８の直鎖状、分岐状又は環状のアルキレン基を示す。Ｒ³⁷はカルボニル基、エステル基、エーテル基、又はハロゲン原子を有していてもよい炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基、又は、カルボニル基、エステル基、エーテル基、ハロゲン原子、炭素数１〜１５のアルキル基又はフッ素化アルキル基を有していてもよい炭素数６〜１５のアリール基のいずれかを示す。）
請求項１０：
請求項９記載の高分子化合物が更に下記一般式（７）で表される繰り返し単位を含むことを特徴とする請求項５乃至９のいずれか１項記載のレジスト保護膜材料。

（式中、Ｒ^31cは水素原子又はメチル基である。Ｒ^38a及びＲ^38bは水素原子、又は炭素数１〜１５の直鎖状、分岐状又は環状のアルキル基であり、Ｒ^38a及びＲ^38bは結合してこれらが結合する炭素原子と共に環を形成することもできる。）
請求項１１：
更に、溶媒を含有することを特徴とする請求項１乃至１０のいずれか１項記載のレジスト保護膜材料。
請求項１２：
溶媒が、炭素数８〜１２のエーテル化合物であることを特徴とする請求項１１記載のレジスト保護膜材料。
請求項１３：
炭素数８〜１２のエーテル化合物として、ジ−ｎ−ブチルエーテル、ジ−イソブチルエーテル、ジ−ｓｅｃ−ブチルエーテル、ジ−ｎ−ペンチルエーテル、ジ−イソペンチルエーテル、ジ−ｓｅｃ−ペンチルエーテル、ジ−ｔ−アミルエーテル、ジ−ｎ−ヘキシルエーテルから選ばれる１種以上の溶媒を用いることを特徴とする請求項１１又は１２記載のレジスト保護膜材料。
請求項１４：
上記エーテル化合物に加えて、炭素数４〜１０の高級アルコールを０．１〜９０質量％混合して用いることを特徴とする請求項１２又は１３記載のレジスト保護膜材料。
請求項１５：
（１）レジスト材料を基板上に塗布する工程と、（２）請求項５乃至１４のいずれか１項に記載のレジスト保護膜材料を用いてフォトレジスト膜上にレジスト保護膜を形成する工程と、（３）加熱処理後、投影レンズとウエハーの間に液体を挿入させ、フォトマスクを介して高エネルギー線で露光する工程と、（４）現像液を用いて現像する工程を含むことを特徴とするパターン形成方法。
請求項１６：
前記露光工程において、投影レンズと基板の間に挿入する液体が水であることを特徴とする請求項１５記載のパターン形成方法。
請求項１７：
露光光源として波長１８０〜２５０ｎｍの範囲の高エネルギー線を用いることを特徴とする請求項１５又は１６記載のパターン形成方法。
請求項１８：
前記現像工程において、アルカリ現像液を用いて現像し、前記フォトレジスト膜にレジストパターンを形成すると同時にフォトレジスト膜上のレジスト保護膜の剥離を行うことを特徴とする請求項１５乃至１７のいずれか１項記載のパターン形成方法。
請求項１９：
マスクブランクスに形成したフォトレジスト層上に保護膜を形成後、真空中で電子ビーム露光し、次いで現像を行うリソグラフィーにおいて、請求項５乃至１４のいずれか１項記載の保護膜材料を用いることを特徴とするパターン形成方法。 That is, the present invention provides the following polymer compound, resist protective film material, and pattern forming method.
Claim 1:
A polymer compound having a repeating unit represented by the following general formula (1) and having a weight average molecular weight in the range of 1,000 to 500,000.

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. X represents any structure represented by the general formulas (X-1) to (X-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. R ⁴ represents a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded. A part of the hydrogen atom may be substituted with a halogen atom, and a part of the methylene group may be substituted with an oxygen atom or a carbonyl group, wherein the general formula (X-1) is R ^2a , Linked to the — (C═O) —O— bond of the repeating unit (1) via any of R ^2b , R ^3a and R ^3b . In general formula (X-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a and R ^7b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a carbon number of 1 to 15. A linear, branched or cyclic monovalent organic group, and two of them may be bonded together to form a ring together with the carbon atom to which they are bonded. Is linked to the — (C═O) —O— bond of the repeating unit (1) via any one of R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b . R ^8a , R ^8b , R ^9a and R ^9b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. It represents a group, bonded two of these together may form a ring together with the carbon atoms to which they are attached. formula (X-3) is R ^{8a, 8b,} R ^9a, repeating units via one of the R ^9b (1) -. Linked to (C = O) -O- bond ^{Incidentally, R 2a, R 2b, R} 3a, R 3b, R 5a, R ^5b , R ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b as a linking group to the — (C═O) —O— bond of the repeating unit (1) In the case of linking, in the above definition, the linking group is a group in which one hydrogen atom contained in the organic group is eliminated and this elimination site is a bond.
Claim 2:
A polymer compound having a weight average molecular weight in the range of 1,000 to 500,000, which has a repeating unit represented by the following general formula (2).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. Y represents any structure represented by the general formulas (Y-1) to (Y-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Y-1) is R ^2a , R ^2b , R ^3a , R ^3b. In the general formula (Y-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a are linked to the — (C═O) —O— bond of the repeating unit (2). R ^7b each independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. Two of these may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Y-2) is represented by R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b is linked to the — (C═O) —O— bond of the repeating unit (2) through R ^7a , R ^8a , R ^8b , R ^9a and R ^9b are each represented by formula (Y-3) Independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms, two of which are bonded to each other A ring may be formed together with the carbon atom of General Formula (Y-3) is represented by — (C═O) — of repeating unit (2) through any of R ^8a , R ^8b , R ^9a and R ^9b. coupled to O- linked .R ¹⁰ is a straight, branched or cyclic alkyl group of 1 to 19 carbon atoms, partially halogen atom hydrogen atom May be substituted, also part of the methylene groups may be replaced by oxygen atom, or a carbonyl group. In ^{addition, R 2a, R 2b, R} 3a, R 3b, R 5a, R 5b, R ^When connecting to the — (C═O) —O— bond of the repeating unit (2) using any one of ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b as a linking group, (In the above definition, the linking group is a group in which one hydrogen atom contained in the organic group is eliminated and this elimination site is a bond.)
Claim 3:
A polymer compound having a weight average molecular weight in the range of 1,000 to 500,000, characterized by having a repeating unit represented by the following general formula (3).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. Z represents any structure represented by the general formulas (Z-1) to (Z-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Z-1) is R ^2a , R ^2b , R ^3a , R ^3b. In the general formula (Z-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a are linked to the — (C═O) —O— bond of the repeating unit (3). R ^7b each independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Z-2) is R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b is linked to the — (C═O) —O— bond of the repeating unit (3) through which R ^8a , R ^8b , R ^9a and R ^9b are each represented by the following formula (Z-3): Independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms, two of which are bonded to each other A ring may be formed together with the carbon atom of General Formula (Z-3) is — (C═O) — of repeating unit (3) through any of R ^8a , R ^8b , R ^9a , and R ^9b. coupled to O- linked .R ¹¹ is hydrogen atom or a number from 1 to 18 linear carbon atoms, a branched or cyclic alkyl group, a part of hydrogen atoms May be substituted with androgenic atom, also a part of the methylene groups is an oxygen atom, or may .R ¹² be substituted by a carbonyl group is a straight 1-19 carbon atoms, branched or cyclic an alkyl group, part of the hydrogen atoms may be substituted with a halogen atom, a part of the methylene groups is an oxygen atom or .R ¹¹ and R ¹² may be substituted by a carbonyl group, the bond A cyclic structure may be formed together with the carbon atom and oxygen atom to which they are bonded, and R ^2a , R ^2b , R ^3a , R ^3b , R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , When any of R ^7b , R ^8a , R ^8b , R ^9a and R ^9b is linked to the — (C═O) —O— bond of the repeating unit (3), the linking group is defined as above. One hydrogen atom contained in the organic group is eliminated, and this elimination site is regarded as a bond. A group. )
Claim 4:
The polymer compound according to any one of claims 1 to 3, further comprising one or more of repeating units represented by the following general formulas (4a) to (4f).

Wherein R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group. R ^13a and R ^13b are a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, R ^13a and R ^13b can be bonded to each other to form a ring together with the carbon atom to which they are bonded, R ¹⁴ is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, fluorine R ¹⁵ is a linear, branched or cyclic fluorinated alkyl group having 1 to ¹⁵ carbon atoms, and R ¹⁶ is an acid labile group.
Claim 5:
A resist protective film material comprising a polymer compound having a repeating unit represented by the following general formula (1).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. X represents any structure represented by the general formulas (X-1) to (X-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. R ⁴ represents a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded. A part of the hydrogen atom may be substituted with a halogen atom, and a part of the methylene group may be substituted with an oxygen atom or a carbonyl group, wherein the general formula (X-1) is R ^2a , Linked to the — (C═O) —O— bond of the repeating unit (1) via any of R ^2b , R ^3a and R ^3b . In general formula (X-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a and R ^7b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a carbon number of 1 to 15. A linear, branched or cyclic monovalent organic group, and two of them may be bonded together to form a ring together with the carbon atom to which they are bonded. Is linked to the — (C═O) —O— bond of the repeating unit (1) via any one of R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b . R ^8a , R ^8b , R ^9a and R ^9b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. It represents a group, bonded two of these together may form a ring together with the carbon atoms to which they are attached. formula (X-3) is R ^{8a, 8b,} R ^9a, repeating units via one of the R ^9b (1) -. Linked to (C = O) -O- bond ^{Incidentally, R 2a, R 2b, R} 3a, R 3b, R 5a, R ^5b , R ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b as a linking group to the — (C═O) —O— bond of the repeating unit (1) In the case of linking, in the above definition, the linking group is a group in which one hydrogen atom contained in the organic group is eliminated and this elimination site is a bond.
Claim 6:
A resist protective film material comprising a polymer compound having a repeating unit represented by the following general formula (2).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. Y represents any structure represented by the general formulas (Y-1) to (Y-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Y-1) is R ^2a , R ^2b , R ^3a , R ^3b. In the general formula (Y-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a are linked to the — (C═O) —O— bond of the repeating unit (2). R ^7b each independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. Two of these may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Y-2) is represented by R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b is linked to the — (C═O) —O— bond of the repeating unit (2) through R ^7a , R ^8a , R ^8b , R ^9a and R ^9b are each represented by formula (Y-3) Independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms, two of which are bonded to each other A ring may be formed together with the carbon atom of General Formula (Y-3) is represented by — (C═O) — of repeating unit (2) through any of R ^8a , R ^8b , R ^9a and R ^9b. coupled to O- linked .R ¹⁰ is a straight, branched or cyclic alkyl group of 1 to 19 carbon atoms, partially halogen atom hydrogen atom May be substituted, also part of the methylene groups may be replaced by oxygen atom, or a carbonyl group. In ^{addition, R 2a, R 2b, R} 3a, R 3b, R 5a, R 5b, R ^When connecting to the — (C═O) —O— bond of the repeating unit (2) using any one of ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b as a linking group, (In the above definition, the linking group is a group in which one hydrogen atom contained in the organic group is eliminated and this elimination site is a bond.)
Claim 7:
A resist protective film material comprising a polymer compound having a repeating unit represented by the following general formula (3).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. Z represents any structure represented by the general formulas (Z-1) to (Z-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Z-1) is R ^2a , R ^2b , R ^3a , R ^3b. In the general formula (Z-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a are linked to the — (C═O) —O— bond of the repeating unit (3). R ^7b each independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Z-2) is R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b is linked to the — (C═O) —O— bond of the repeating unit (3) through which R ^8a , R ^8b , R ^9a and R ^9b are each represented by the following formula (Z-3): Independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms, two of which are bonded to each other A ring may be formed together with the carbon atom of General Formula (Z-3) is — (C═O) — of repeating unit (3) through any of R ^8a , R ^8b , R ^9a , and R ^9b. coupled to O- linked .R ¹¹ is hydrogen atom or a number from 1 to 18 linear carbon atoms, a branched or cyclic alkyl group, a part of hydrogen atoms May be substituted with androgenic atom, also a part of the methylene groups is an oxygen atom, or may .R ¹² be substituted by a carbonyl group is a straight 1-19 carbon atoms, branched or cyclic an alkyl group, part of the hydrogen atoms may be substituted with a halogen atom, a part of the methylene groups is an oxygen atom or .R ¹¹ and R ¹² may be substituted by a carbonyl group, the bond A cyclic structure may be formed together with the carbon atom and oxygen atom to which they are bonded, and R ^2a , R ^2b , R ^3a , R ^3b , R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , When any of R ^7b , R ^8a , R ^8b , R ^9a and R ^9b is linked to the — (C═O) —O— bond of the repeating unit (3), the linking group is defined as above. One hydrogen atom contained in the organic group is eliminated, and this elimination site is regarded as a bond. A group. )
Claim 8:
Furthermore, the high molecular compound which has 1 or 2 or more of the repeating units represented by the following general formula (4a)-(4f) is included, The any one of Claims 5 thru | or 7 characterized by the above-mentioned. Resist protective film material.

Wherein R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group. R ^13a and R ^13b are a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, R ^13a and R ^13b can be bonded to each other to form a ring together with the carbon atom to which they are bonded, R ¹⁴ is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, fluorine R ¹⁵ is a linear, branched or cyclic fluorinated alkyl group having 1 to ¹⁵ carbon atoms, and R ¹⁶ is an acid labile group.
Claim 9:
The resist protective film material according to any one of claims 5 to 8, comprising a polymer compound having a repeating unit represented by the following general formula (5) or (6).

(Wherein R ^31a and R ^31b are a hydrogen atom or a methyl group. R ³² is a single bond, an alkylene group having 1 to 4 carbon atoms, a phenylene group, —C (═O) —O—, —C (= O) -NH- R ³³ is a single bond or a linear, branched or cyclic alkylene group having 1 to 8 carbon atoms R ^{34a to} R ^34d and R ^{36a to} R ^36c is each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an alkenyl group, an oxoalkyl group or an oxoalkenyl group, an aryl group having 6 to 20 carbon atoms, Any one of 12 aralkyl groups or aryloxoalkyl groups, and some or all of the hydrogen atoms may be substituted with alkoxy groups, and R ^{34a to} R ^34d and R ^{36a to} R ^36c may be Nitrogen atom, ether group, ester group, hydroxy Or two of which may contain a carboxyl group .R ^34a to R ^34d and R ^36a to R ^36c, taken together may form a ring together with the nitrogen atom to which they are attached, in which case each independently an alkylene group of 3 to 15 carbon atoms, or .R ³⁵ showing a heteroaromatic ring having a nitrogen atom in the formula in the ring is linear C1-8, branched or cyclic alkylene group R ³⁷ represents a carbonyl group, an ester group, an ether group, or a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms which may have a halogen atom, or a carbonyl group, an ester group, It represents any of an ether group, a halogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms which may have a fluorinated alkyl group.)
Claim 10:
The resist protective film material according to any one of claims 5 to 9, wherein the polymer compound according to claim 9 further contains a repeating unit represented by the following general formula (7).

(Wherein, R ^31c is a hydrogen atom or a methyl group .R ^38a and R ^38b is a hydrogen atom, or of the straight, a branched or cyclic alkyl group, R ^38a and R ^38b Can also combine to form a ring with the carbon atoms to which they are attached.)
Claim 11:
The resist protective film material according to any one of claims 1 to 10, further comprising a solvent.
Claim 12:
The resist protective film material according to claim 11, wherein the solvent is an ether compound having 8 to 12 carbon atoms.
Claim 13:
As an ether compound having 8 to 12 carbon atoms, di-n-butyl ether, di-isobutyl ether, di-sec-butyl ether, di-n-pentyl ether, di-isopentyl ether, di-sec-pentyl ether, di-t 13. The resist protective film material according to claim 11 or 12, wherein at least one solvent selected from amyl ether and di-n-hexyl ether is used.
Claim 14:
14. The resist protective film material according to claim 12, wherein 0.1 to 90% by mass of a higher alcohol having 4 to 10 carbon atoms is used in addition to the ether compound.
Claim 15:
(1) a step of applying a resist material on the substrate; (2) a step of forming a resist protective film on the photoresist film using the resist protective film material according to any one of claims 5 to 14; And (3) a step of inserting a liquid between the projection lens and the wafer after the heat treatment, and exposing with a high energy beam through a photomask, and (4) a step of developing with a developer. A pattern forming method.
Claim 16:
The pattern forming method according to claim 15, wherein the liquid inserted between the projection lens and the substrate in the exposure step is water.
Claim 17:
17. The pattern forming method according to claim 15, wherein a high energy ray having a wavelength in the range of 180 to 250 nm is used as the exposure light source.
Claim 18:
18. The development step according to claim 15, wherein 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. The pattern forming method according to claim 1.
Claim 19:
Use of the protective film material according to any one of claims 5 to 14 in lithography in which a protective film is formed on a photoresist layer formed on a mask blank, followed by electron beam exposure in a vacuum and then developing. A characteristic pattern forming method.

  As described above, the present invention provides a resist protective film material having a cyclic acetal structure and a base polymer thereof. This polymer material has excellent transparency to radiation with a wavelength of 200 nm or less, and various performances such as water repellency, water slidability, fat solubility, acid decomposability, and hydrolyzability can be adjusted by selecting the resin structure And can be produced from raw materials that are easy to obtain and handle. In addition, since the resist protective film material of the present invention has a high receding contact angle, the dissolution of resist components and the penetration of water are suppressed, and there are few development defects, and immersion lithography with a good resist pattern shape after development is realized. be able to.

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｘは一般式（Ｘ−１）〜（Ｘ−３）で表されるいずれかの構造、Ｙは一般式（Ｙ−１）〜（Ｙ−３）で表されるいずれかの構造、Ｚは一般式（Ｚ−１）〜（Ｚ−３）で表されるいずれかの構造を表す。一般式（Ｘ−１），（Ｙ−１），（Ｚ−１）の中でＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。Ｒ⁴は炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、メチレン基の一部が酸素原子又はカルボニル基で置換されていてもよい。一般式（Ｘ−１），（Ｙ−１），（Ｚ−１）はそれぞれＲ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3bのいずれかを介して繰り返し単位（１）〜（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｘ−２），（Ｙ−２），（Ｚ−２）の中でＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｘ−２），（Ｙ−２），（Ｚ−２）はそれぞれＲ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7bのいずれかを介して繰り返し単位（１）〜（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。一般式（Ｘ−３），（Ｙ−３），（Ｚ−３）の中でＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bはそれぞれ独立に単結合、水素原子、水酸基、ハロゲン原子、又は炭素数１〜１５の直鎖状、分岐状又は環状の一価の有機基を表し、これらのうち２個が互いに結合してこれらが結合する炭素原子と共に環を形成してもよい。一般式（Ｘ−３），（Ｙ−３），（Ｚ−３）はそれぞれＲ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを介して繰り返し単位（１）〜（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する。Ｒ¹⁰は炭素数１〜１９の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、また、メチレン基の一部が酸素原子、又はカルボニル基で置換されていてもよい。Ｒ¹¹は水素原子又は炭素数１〜１８の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、また、メチレン基の一部が酸素原子、又はカルボニル基で置換されていてもよい。Ｒ¹²は炭素数１〜１９の直鎖状、分岐状又は環状のアルキル基であり、水素原子の一部がハロゲン原子で置換されていてもよく、また、メチレン基の一部が酸素原子、又はカルボニル基で置換されていてもよい。Ｒ¹¹とＲ¹²は結合してこれらが結合する炭素原子及び酸素原子と共に環状構造を形成してもよい。なお、Ｒ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3b、Ｒ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7b、Ｒ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bのいずれかを連結基として繰り返し単位（１）〜（３）の−（Ｃ＝Ｏ）−Ｏ−結合に連結する場合、当該連結基は、上記定義において、その有機基に含まれる水素原子が１個脱離し、この脱離箇所が結合手とされた基である。） [Configuration of polymer compound for resist protective film material]
The polymer compound used for the resist protective film material of the present invention is characterized by containing any one of the repeating units represented by the following general formulas (1) to (3).

(Wherein R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group. X is any structure represented by the general formulas (X-1) to (X-3), Y is a general formula (Y -1) to (Y-3), Z represents any one of the structures represented by general formulas (Z-1) to (Z-3). ), (Y-1), (Z-1), R ^2a , R ^2b , R ^3a , R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a straight chain having 1 to 15 carbon atoms. R ⁴ represents a chain, branched or cyclic monovalent organic group, two of which may be bonded to each other to form a ring together with the carbon atom to which they are bonded. A linear, branched or cyclic alkyl group in which part of the hydrogen atom may be substituted with a halogen atom, and part of the methylene group is an oxygen atom or The general formulas (X-1), (Y-1), and (Z-1) may each be a repeating unit via any one of R ^2a , R ^2b , R ^3a , and R ^3b. Linked to the — (C═O) —O— bond of (1) to (3), R ^5a , R ^5b , and R ^2a in general formulas (X-2), (Y-2), and (Z-2) R ^6a , R ^6b , R ^7a and R ^7b each independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms, Two of these may be bonded to each other to form a ring together with the carbon atom to which they are bonded.General formulas (X-2), (Y-2), and (Z-2) are R ^5a , R Linked to the — (C═O) —O— bond of the repeating units (1) to (3) through any of ^5b , R ^6a , R ^6b , R ^7a , R ^7b , general formula (X-3) , (Y-3), In (Z-3), R ^8a , R ^8b , R ^9a and R ^9b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic group having 1 to 15 carbon atoms. It represents a monovalent organic group, and two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, represented by the general formulas (X-3), (Y-3), (Z- 3) is connected to the — (C═O) —O— bond of the repeating units (1) to (3) via any of R ^8a , R ^8b , R ^9a and R ^9b , and R ¹⁰ is the number of carbon atoms. 1 to 19 linear, branched or cyclic alkyl group, part of hydrogen atom may be substituted with halogen atom, part of methylene group substituted with oxygen atom or carbonyl group May be. R ¹¹ is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, a part of the hydrogen atom may be substituted with a halogen atom, and a part of the methylene group is It may be substituted with an oxygen atom or a carbonyl group. R ¹² is a linear, branched or cyclic alkyl group having 1 to 19 carbon atoms, part of the hydrogen atoms may be substituted with a halogen atom, and part of the methylene group is an oxygen atom, Alternatively, it may be substituted with a carbonyl group. R ¹¹ and R ¹² may combine to form a cyclic structure together with the carbon atom and oxygen atom to which they are bonded. R ^2a , R ^2b , R ^3a , R ^3b , R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b are used as a linking group. In the case of linking to the — (C═O) —O— bond of the repeating units (1) to (3), in the above definition, the linking group is desorbed by one hydrogen atom contained in the organic group. The separation point is a group with a bond. )

In the above formulas (X-1), (Y-1), (Z-1), R ^2a , R ^2b , R ^3a , R ^3b having 1 to 15 carbon atoms in a straight, branched or cyclic monovalent state Specific examples of the organic group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, tert-amyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexyl group, cyclohexylmethyl group, cyclohexyl Ethyl group, cyclohexylbutyl group, methylcyclohexylmethyl group, ethylcyclohexylmethyl group, ethylcyclohexylethyl group, bicyclyl [2.2.1] heptyl group, bicyclo [2.2.1] heptylmethyl group, bicyclo [2.2.1] heptylethyl group, bicyclo [2.2.1] heptylbutyl group, methylbicyclo [2 2.1] heptylmethyl group, ethylbicyclo [2.2.1] heptylmethyl group, ethylbicyclo [2.2.1] heptylethyl group, bicyclo [2.2.2] octyl group, bicyclo [2. 2.2] octylmethyl group, bicyclo [2.2.2] octylethyl group, bicyclo [2.2.2] octylbutyl group, methylbicyclo [2.2.2] octylmethyl group, ethylbicyclo [2. 2.2] octylmethyl group, ethylbicyclo [2.2.2] octylethyl group, tricyclo [5.2.1.0 ^2,6 ] decyl group, tricyclo [5.2.1.0 ^2,6 ] Decylmethyl group, Rishikuro [5.2.1.0 ^{2, 6]} Deshiruechiru group, tricyclo [5.2.1.0 ^{2, 6]} Deshirubuchiru group, methyltricyclo [5.2.1.0 ^{2, 6]} Deshirumechiru group, Ethyltricyclo [5.2.1.0 ^2,6 ] decylmethyl group, ethyltricyclo [5.2.1.0 ^2,6 ] decylethyl group, adamantyl group, adamantylmethyl group, adamantylethyl group, adamantylbutyl group Methyl adamantylmethyl group, ethyladamantylmethyl group, ethyladamantylethyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylmethyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylethyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylbutyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylmethyl group, ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylmethyl group, ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] alkyl group such as dodecylethyl group, aryl group such as phenyl group, methylphenyl group, naphthyl group, anthryl group, phenanthryl group, aralkyl group such as benzyl group, diphenylmethyl group, phenethyl group, methoxy group, Examples thereof include alkoxy groups such as ethoxy group and propoxy group, and acyloxy groups such as formyloxy group and acetoxy group. In these groups, some of the hydrogen atoms are substituted with halogen atoms, alkyl groups, aryl groups, alkoxy groups, alkoxycarbonyl groups, oxo groups, alkoxyalkyl groups, acyloxy groups, acyloxyalkyl groups, alkoxyalkoxy groups, etc. May be. Of these, a hydrogen atom, a hydroxyl group, a halogen atom, a methyl group, an ethyl group, a propyl group, a tert-butyl group, and a perfluoroalkyl group are particularly preferable.

R ^2a , R ^2b , R ^3a and R ^3b may be combined in any combination and at least two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded. Typical examples of combinations that form a ring include R ^2a and R ^2b , R ^2a and R ^3a , R ^2a and R ^3b , R ^2b and R ^3a , R ^2b and R ^3b , R ^3a and R ^3b. It is done. In this case, the ring formed is cyclopropane, cyclobutane, cyclopentane, cyclohexane, bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, tricyclo [5.2.1.0 ^{2 , 6} ] decane, adamantane, tetracyclo [4.4.0.1 ^2,5 . Examples include alicyclic hydrocarbons having 3 to 12 carbon atoms such as 1 ^7,10 ] dodecane, and may include condensed rings containing these. In these alicyclic hydrocarbons, some of the hydrogen atoms are hydroxyl groups, halogen atoms, alkyl groups, aryl groups, alkoxy groups, alkoxycarbonyl groups, oxo groups, alkoxyalkyl groups, acyloxy groups, acyloxyalkyl groups, alkoxy groups. It may be substituted with an alkoxy group or the like.

As specific examples of R ⁴ , the above-mentioned —CO—R ¹⁰ and —CH (R ¹¹ ) —OR ¹² are particularly desirable, but in addition, methyl group, ethyl group, propyl group, isopropyl group, n-butyl Group, sec-butyl group, tert-butyl group, tert-amyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, icosanyl group, Cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group, methylcyclohexylmethyl group, ethylcyclohexylmethyl group, ethylcyclohexylethyl A group, a bicyclo [2.2.1] heptyl group, Trifluoromethyl group, 2,2,2-trifluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 2-methoxyethyl group, 2- (hexafluoroisopropoxy) ethyl group, 2- Examples thereof include an acetoxyethyl group and an acetonyl group. By selecting an optimum structure as R ⁴ , various properties such as water repellency and fat solubility can be adjusted according to the required performance.

R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b and R ^8a , R ^8b , R ^9a , R ^9b can be exemplified by those similar to R ^2a , R ^2b , R ^3a , R ^3b , respectively. However, as a typical example of the combination that forms a ring, for (X-2), (Y-2), and (Z-2), R ^5a and R ^5b , R ^5a and R ^6a , R ^5a and R ^6b , R ^5b and R ^6a , R ^5b and R ^6b , R ^6a and R ^6b , R ^6a and R ^7a , R ^6a and R ^7b , R ^6b and R ^7a , R ^6b and R ^7b , R ^7a and R ^7b , (X-3), (Y-3), and (Z-3) include R ^8a and R ^8b , and R ^9a and R ^9b .

Specific examples of the alkyl group for R ¹⁰ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, isobutyl group, tert-amyl group, and n-pentyl group. , Neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, nonadecyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclopentylmethyl group, cyclopentylethyl group, Cyclopentylbutyl group, cyclohexyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group, methylcyclohexylmethyl group, ethylcyclohexylmethyl group, ethylcyclohexylethyl group, bicyclo [2.2.1] heptyl group, trifluoromethyl group, 2,2,2-tri Fluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 1-methyl-2,2,2-trifluoroethyl group, 2-methoxyethyl group, 2- (hexafluoroisopropoxy) ethyl group, Examples include 2-acetoxyethyl group and acetonyl group. By selecting an optimum structure as R ¹⁰ , various properties such as alkali hydrolyzability, water repellency, and fat solubility can be adjusted according to the required performance.

Specific examples of the alkyl group of R ¹¹ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, isobutyl group, tert-amyl group, and n-pentyl group. 2-pentyl group, 3-pentyl group, neopentyl group, n-hexyl group, 2-hexyl group, 3-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, octadecyl Group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group, methylcyclohexylmethyl group, ethylcyclohexylmethyl group, ethyl Cyclohexylethyl group, bicycl [2.2.1] heptyl group, trifluoromethyl group, 2,2,2-trifluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 1-methyl-2,2,2 Examples include -trifluoroethyl group, 2-methoxyethyl group, 2- (hexafluoroisopropoxy) ethyl group, 2-acetoxyethyl group, and acetonyl group.

Specific examples of the alkyl group for R ¹² include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, tert-amyl group, n-pentyl group, n- Hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexyl group, cyclohexylmethyl Group, cyclohexylethyl group, cyclohexylbutyl group, methylcyclohexylmethyl group, ethylcyclohexylmethyl group, ethylcyclohexylethyl group, bicyclo [2.2.1] heptyl group, bicyclo [2.2.1] heptylmethyl group, bicyclo [ 2.2.1] heptylethyl group, bi Black [2.2.1] heptylbutyl group, methylbicyclo [2.2.1] heptylmethyl group, ethylbicyclo [2.2.1] heptylmethyl group, ethylbicyclo [2.2.1] heptylethyl group , Bicyclo [2.2.2] octyl group, bicyclo [2.2.2] octylmethyl group, bicyclo [2.2.2] octylethyl group, bicyclo [2.2.2] octylbutyl group, methylbicyclo [2.2.2] Octylmethyl group, ethylbicyclo [2.2.2] octylmethyl group, ethylbicyclo [2.2.2] octylethyl group, tricyclo [5.2.1.0 ^2,6 ] Decyl group, tricyclo [5.2.1.0 ^2,6 ] decylmethyl group, tricyclo [5.2.1.0 ^2,6 ] decylethyl group, tricyclo [5.2.1.0 ^2,6 ] decylbutyl group , Methyltricyclo [5.2.1.0 ^2,6 ] decylmethyl group, ethyltricyclo [5.2.1.0 ^2,6 ] decylmethyl group, ethyltricyclo [5.2.1.0 ^2,6 ] decylethyl group Adamantyl group, adamantylmethyl group, adamantylethyl group, adamantylbutyl group, methyladamantylmethyl group, ethyladamantylmethyl group, ethyladamantylethyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylmethyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylethyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylbutyl group, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylmethyl group, ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylmethyl group, ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecylethyl group, trifluoromethyl group, 2,2,2-trifluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 1-methyl-2,2,2- Examples thereof include a trifluoroethyl group, a 2-methoxyethyl group, a 2- (hexafluoroisopropoxy) ethyl group, a 2-acetoxyethyl group, a 2- (1-adamantylcarbonyloxy) ethyl group, and an acetonyl group.

R ¹¹ and R ¹² may be bonded to form a cyclic structure together with the carbon atom and oxygen atom to which they are bonded. In this case, specific examples of the cyclic structure formed by the bond include tetrahydrofuran ring, methyltetrahydrofuran Examples include a ring, a methoxytetrahydrofuran ring, a tetrahydropyran ring, a methyltetrahydropyran ring, a methoxytetrahydropyran ring, and a 1,4-dioxane ring. By selecting an optimum structure as R ¹⁰ and R ¹¹ , various properties such as acid decomposability, water repellency, and fat solubility can be adjusted according to the required performance.

Specific examples of the repeating units of the above formulas (1) to (3) include the following, but are not limited thereto.

（式中、Ｒ¹は前述と同様である。）

(Wherein R ¹ is the same as described above.)

In the polymer compound used for the resist protective film material of the present invention, the repeating units represented by the general formulas (1) to (3) exhibit excellent water repellency and water slidability. In the polymer compound having a repeating unit represented by the general formulas (1) to (3), R ^{4 in} the general formula (1), R ¹⁰ in the general formula (2), and in the general formula (3) It is easy to control the structure of R ¹¹ and R ^{12 such} as carbon chain length, degree of branching, fluorine number, etc., and it is possible to produce a polymer compound according to the water repellency and sliding performance required as a resist protective film material. .

  In these polymer compounds, alkali hydrolyzability can be imparted as necessary, and in that case, it is preferable to include a repeating unit represented by the above formula (2). The hemiacetal hydroxyl group has a higher acidity than the alcohol hydroxyl group, but the ester bond in the above formula (2) has a hemiacetal hydroxyl group and a carboxylic acid that have a higher acidity due to the bonding of five fluorine atoms to the adjacent carbon. Since it is an ester with an acid, that is, a mixed acid anhydride, it is significantly more susceptible to alkaline hydrolysis than an ordinary alcohol and carboxylic acid ester. For example, it is easily hydrolyzed by an alkali developer or the like. It is considered a thing.

Moreover, in the above-described polymer compound, acid decomposability can be imparted as necessary. In this case, the polymer compound of the present invention includes a repeating unit represented by the above formula (3). It is preferable. In the above formula (3), there is an acid-unstable acetal structure —O—CH (R ¹¹ ) —OR ¹² ; Conceivable.

  When the ester bond in the above formula (2) is hydrolyzed, or when the acetal structure in the above formula (3) is decomposed, a highly hydrophilic hemiacetal structure is formed. The subsequent contact angle decreases, contributing to the reduction of blob defects.

（式中、Ｒ¹は水素原子、メチル基又はトリフルオロメチル基である。Ｒ^13a及びＲ^13bは水素原子、又は炭素数１〜１５の直鎖状、分岐状又は環状のアルキル基であり、Ｒ^13aとＲ^13bは互いに結合してこれらが結合する炭素原子と共に環を形成することもできる。Ｒ¹⁴は水素原子、炭素数１〜１５の直鎖状、分岐状又は環状のアルキル基又はフッ素化アルキル基、又は酸不安定基である。Ｒ¹⁵は炭素数１〜１５の直鎖状、分岐状又は環状のフッ素化アルキル基である。Ｒ¹⁶は酸不安定基である。） In the polymer compound used as the resist protective film material of the present invention, in addition to the repeating units represented by the general formulas (1) to (3), one repeating unit represented by the following general formulas (4a) to (4f) By coexisting two or more, a polymer compound that is further excellent in water repellency, water slidability, alkali solubility, and contact angle after development can be realized.

Wherein R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group. R ^13a and R ^13b are a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, R ^13a and R ^13b can be bonded to each other to form a ring together with the carbon atom to which they are bonded, R ¹⁴ is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, fluorine R ¹⁵ is a linear, branched or cyclic fluorinated alkyl group having 1 to ¹⁵ carbon atoms, and R ¹⁶ is an acid labile group.

In the above formulas (4a) to (4f), specific examples of the linear, branched or cyclic alkyl group having 1 to 15 carbon atoms of R ^13a , R ^13b and R ¹⁴ include a methyl group, an ethyl group, n -Propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, tert-amyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl Group, n-decyl group, cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group, adamantyl group and the like are used. R ^13a and R ^13b can be bonded to each other to form a non-aromatic ring together with the carbon atom to which they are bonded. In this case, R ^13a and R ^13b are alkylene groups, and One having one hydrogen atom is used, and examples of the ring include a cyclopentyl group and a cyclohexyl group.

The linear, branched or cyclic fluorinated alkyl group having 1 to ¹⁵ carbon atoms of R ¹⁴ and R ¹⁵ has a form in which part or all of the hydrogen atoms of the above alkyl group are substituted with fluorine atoms. Specific examples include trifluoromethyl group, 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 1,1,2,2,3,3,3-heptafluoro. Propyl group, 1H, 1H, 3H-tetrafluoropropyl group, 1H, 1H, 5H-octafluoropentyl group, 1H, 1H, 7H-dodecafluoroheptyl group, 2- (perfluorobutyl) ethyl group, 2- (par Examples include a fluorohexyl) ethyl group, a 2- (perfluorooctyl) ethyl group, a 2- (perfluorodecyl) ethyl group, and the like.

（式中、Ｒ^L01及びＲ^L02は水素原子又は炭素数１〜１８、好ましくは１〜１０の直鎖状、分岐状又は環状のアルキル基を示す。Ｒ^L03は炭素数１〜１８、好ましくは炭素数１〜１０の酸素原子等のヘテロ原子を有してもよい一価の炭化水素基を示し、直鎖状、分岐状又は環状のアルキル基、これらの水素原子の一部が水酸基、アルコキシ基、オキソ基、アミノ基、アルキルアミノ基等に置換されたものを挙げることができる。Ｒ^L04は炭素数４〜２０、好ましくは炭素数４〜１５の三級アルキル基、各アルキル基がそれぞれ炭素数１〜６のトリアルキルシリル基、炭素数４〜２０のオキソアルキル基又は上記一般式（Ｌ１）で示される基を示す。Ｒ^L05は炭素数１〜１０の置換されていてもよい直鎖状、分岐状又は環状のアルキル基又は炭素数６〜２０の置換されていてもよいアリール基を示す。Ｒ^L06は炭素数１〜１０の置換されていてもよい直鎖状、分岐状又は環状のアルキル基又は炭素数６〜２０の置換されていてもよいアリール基である。Ｒ^L07〜Ｒ^L16はそれぞれ独立に水素原子又は炭素数１〜１５の一価の炭化水素基を示す。ｙは０〜６の整数である。ｍは０又は１、ｎは０〜３の整数であり、２ｍ＋ｎ＝２又は３である。なお、破線は結合手を示す。） Next, the acid labile group of R ¹⁴ and R ¹⁶ will be described.
Although various groups can be used as the acid labile group, specifically, a group represented by the following general formulas (L1) to (L4), a tertiary alkyl having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms. Groups, each alkyl group may be a trialkylsilyl group having 1 to 6 carbon atoms, an oxoalkyl group having 4 to 20 carbon atoms, and the like.

(In the formula, R ^L01 and R ^L02 represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, preferably 1 to 10. R ^L03 represents 1 to 18 carbon atoms, preferably A monovalent hydrocarbon group which may have a hetero atom such as an oxygen atom having 1 to 10 carbon atoms, a linear, branched or cyclic alkyl group, a part of these hydrogen atoms being a hydroxyl group, an alkoxy group Group, oxo group, amino group, alkylamino group, etc. R ^L04 is a tertiary alkyl group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, and each alkyl group is A trialkylsilyl group having 1 to 6 carbon atoms, an oxoalkyl group having 4 to 20 carbon atoms, or a group represented by the above general formula (L1), R ^L05 is an ^optionally substituted one having 1 to 10 carbon atoms; Chain, branched or cyclic alkyl group or 6 carbon atoms .R ^L06 showing a an optionally substituted aryl group 20 have been substituted 6-20 alkyl group carbon atoms or a substituted or unsubstituted, linear, branched or cyclic C1-10 R ^{L07 to} R ^L16 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 15 carbon atoms, y is an integer of 0 to 6, m is 0 or 1, n is an integer of 0 to 3, and 2m + n = 2 or 3. The broken line indicates a bond.)

In the formula (L1), specific examples of R ^L01 and R ^L02 include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclopentyl group, cyclohexyl group, Examples include 2-ethylhexyl group, n-octyl group, adamantyl group and the like.
R ^L03 represents a monovalent hydrocarbon group which may have a hetero atom such as an oxygen atom having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and is a linear, branched or cyclic alkyl group, Examples in which a part of these hydrogen atoms are substituted with a hydroxyl group, an alkoxy group, an oxo group, an amino group, an alkylamino group, and the like can be given. Specifically, a linear, branched or cyclic alkyl group Examples thereof include those similar to R ^L01 and R ^L02 above, and examples of the substituted alkyl group include the following groups.

R ^L01 and R ^L02 , R ^L01 and R ^L03 , R ^L02 and R ^L03 may be bonded to each other to form a ring together with the carbon atom or oxygen atom to which they are bonded. R ^L01 , R ^L02 and R ^L03 involved in the formation each represent a linear or branched alkylene group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms.

In the formula (L2), specific examples of the tertiary alkyl group of R ^L04 include tert-butyl group, tert-amyl group, 1,1-diethylpropyl group, 2-cyclopentylpropan-2-yl group, and 2-cyclohexyl. Propan-2-yl group, 2- (bicyclo [2.2.1] heptan-2-yl) propan-2-yl group, 2- (adamantan-1-yl) propan-2-yl group, 1-ethyl Cyclopentyl group, 1-butylcyclopentyl group, 1-ethylcyclohexyl group, 1-butylcyclohexyl group, 1-ethyl-2-cyclopentenyl group, 1-ethyl-2-cyclohexenyl group, 2-methyl-2-adamantyl group, Examples thereof include a 2-ethyl-2-adamantyl group. Specific examples of the trialkylsilyl group include trimethylsilyl group, triethylsilyl group, dimethyl-tert-butylsilyl group and the like. Specific examples of the oxoalkyl group include 3-oxocyclohexyl group, 4-methyl-2 Examples thereof include -oxooxan-4-yl group and 5-methyl-2-oxooxolan-5-yl group.

In the formula (L3), specific examples of the linear, branched or cyclic alkyl group having 1 to 10 carbon atoms which may be substituted in R ^L05 include a methyl group, an ethyl group, a propyl group, an isopropyl group, Straight chain such as n-butyl group, sec-butyl group, tert-butyl group, tert-amyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group, bicyclo [2.2.1] heptyl group , Branched or cyclic alkyl groups, some of these hydrogen atoms are hydroxyl, alkoxy, carboxy, alkoxycarbonyl, oxo, amino, alkylamino, cyano, mercapto, alkylthio, sulfo Examples thereof include those substituted with a group or the like, or those wherein a part of these methylene groups is substituted with an oxygen atom or a sulfur atom. Specific examples of the optionally substituted aryl group having 6 to 20 carbon atoms include a phenyl group, a methylphenyl group, a naphthyl group, an anthryl group, a phenanthryl group, and a pyrenyl group.

Specific examples of the linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms that may be substituted or an aryl group having 6 to 20 carbon atoms that may be substituted in R ^L06 in formula (L4) Examples thereof include those similar to R ^L05 .
In R ^{L07 to} R ^L16 , specific examples of the monovalent hydrocarbon group having 1 to 15 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert- Butyl group, tert-amyl group, n-pentyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group, cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group A linear, branched or cyclic alkyl group such as a cyclohexylmethyl group, a cyclohexylethyl group, and a cyclohexylbutyl group, and some of these hydrogen atoms are a hydroxyl group, an alkoxy group, a carboxy group, an alkoxycarbonyl group, an oxo group, an amino group, Group, alkylamino group, cyano group, mercapto group, alkylthio group, sulfo group, etc. Or the like can be exemplified those.
R ^{L07 to} R ^L16 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded (for example, R ^L07 and R ^L08 , R ^L07 and R ^L09 , R ^L08 and R ^L10 , R ^L09 and R ^L10 , R ^L11 and R ^L12 , R ^L13 and R ^L14, etc.), in which case the group involved in ring formation is a divalent hydrocarbon group having 1 to 15 carbon atoms, specifically the monovalent The thing which remove | eliminated one hydrogen atom from what was illustrated by the hydrocarbon group of this can be illustrated. R ^{L07 to} R ^L16 may be bonded to each other adjacent to each other to form a double bond (for example, R ^L07 and R ^L09 , R ^L09 and R ^L15 , R ^L13 and R ^L15 etc.).

Of the acid labile groups represented by the formula (L1), specific examples of the linear or branched ones include the following groups.

  Among the acid labile groups represented by the above formula (L1), specific examples of cyclic groups include tetrahydrofuran-2-yl group, 2-methyltetrahydrofuran-2-yl group, tetrahydropyran-2-yl group, 2 -A methyltetrahydropyran-2-yl group etc. can be illustrated.

  Specific examples of the acid labile group of the above formula (L2) include tert-butoxycarbonyl group, tert-butoxycarbonylmethyl group, tert-amyloxycarbonyl group, tert-amyloxycarbonylmethyl group, 1,1-diethyl. Propyloxycarbonyl group, 1,1-diethylpropyloxycarbonylmethyl group, 1-ethylcyclopentyloxycarbonyl group, 1-ethylcyclopentyloxycarbonylmethyl group, 1-ethyl-2-cyclopentenyloxycarbonyl group, 1-ethyl-2 Examples include -cyclopentenyloxycarbonylmethyl group, 1-ethoxyethoxycarbonylmethyl group, 2-tetrahydropyranyloxycarbonylmethyl group, 2-tetrahydrofuranyloxycarbonylmethyl group and the like.

  Specific examples of the acid labile group of the above formula (L3) include 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-n-propylcyclopentyl, 1-isopropylcyclopentyl, 1-n-butylcyclopentyl, 1-sec- Butylcyclopentyl, 1-cyclohexylcyclopentyl, 1- (4-methoxy-n-butyl) cyclopentyl, 1- (bicyclo [2.2.1] heptan-2-yl) cyclopentyl, 1- (7-oxabicyclo [2. 2.1] heptan-2-yl) cyclopentyl, 1-methylcyclohexyl, 1-ethylcyclohexyl, 3-methyl-1-cyclopenten-3-yl, 3-ethyl-1-cyclopenten-3-yl, 3-methyl- 1-cyclohexen-3-yl, 3-ethyl-1-cyclohexen-3-yl, etc. It can be exemplified.

（式中、Ｒ^L41はそれぞれ独立に炭素数１〜１０の直鎖状、分岐状又は環状のアルキル基等の一価炭化水素基を示す。破線は結合位置及び結合方向を示す。） As the acid labile group of the above formula (L4), groups represented by the following formulas (L4-1) to (L4-4) are particularly preferable.

(In the formula, R ^L41 each independently represents a monovalent hydrocarbon group such as a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. The broken lines indicate the bonding position and bonding direction.)

In the above formulas (L4-1) to (L4-4), specific examples of the monovalent hydrocarbon group of R ^L41 include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group. Tert-butyl group, tert-amyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group and the like.

  In the general formulas (L4-1) to (L4-4), enantiomers and diastereomers may exist, but the general formulas (L4-1) to (L4-4) may exist. ) Represents all of these stereoisomers. These stereoisomers may be used alone or as a mixture.

（式中、Ｒ^L41は前述と同様である。） For example, the general formula (L4-3) represents one or a mixture of two selected from the groups represented by the following general formulas (L4-3-1) and (L4-3-2). To do.

(In the formula, R ^L41 is the same as described above.)

（式中、Ｒ^L41は前述と同様である。） The general formula (L4-4) represents one or a mixture of two or more selected from groups represented by the following general formulas (L4-4-1) to (L4-4-4). And

(In the formula, R ^L41 is the same as described above.)

  The general formulas (L4-1) to (L4-4), (L4-3-1), (L4-3-2), and formulas (L4-4-1) to (L4-4-4) are Their enantiomers and enantiomeric mixtures are also shown representatively.

  In addition, the bonds of formulas (L4-1) to (L4-4), (L4-3-1), (L4-3-2), and formulas (L4-4-1) to (L4-4-4) High reactivity in the acid-catalyzed elimination reaction is realized by the fact that each direction is on the exo side with respect to the bicyclo [2.2.1] heptane ring (see JP 2000-336121 A). In the production of a monomer having a tertiary exo-alkyl group having a bicyclo [2.2.1] heptane skeleton as a substituent, the following general formulas (L4-1-endo) to (L4-4-endo) are used. In some cases, a monomer substituted with the indicated endo-alkyl group may be included, but in order to achieve good reactivity, the exo ratio is preferably 50% or more, and the exo ratio is 80% or more. More preferably.

（式中、Ｒ^L41は前述と同様である。）

(In the formula, R ^L41 is the same as described above.)

Specific examples of the acid labile group of the above formula (L4) include the following groups.

Further, tertiary alkyl groups having 4 to 20 carbon atoms, trialkylsilyl groups each having 1 to 6 carbon atoms, and oxoalkyl groups having 4 to 20 carbon atoms are specifically exemplified as R ^L04 . The thing similar to a thing etc. can be illustrated.

Specific examples of the repeating units of the above formulas (4a) to (4f) include the following, but are not limited thereto.

（式中、Ｒ¹は前述と同様である。）

(Wherein R ¹ is the same as described above.)

  The polymer compound of the present invention can exhibit sufficient performance only by the combination of the repeating units represented by the above formulas (1) to (3) and (4a) to (4f). And the following general formulas (8a) to (8e), (9a) to (9e), (10a) to (10c), (11a) to (11c) ) Or a combination of two or more repeating units represented by

（式中、Ｒ¹⁷は炭素数１〜１５のアルキル基又はフッ素化アルキル基である。Ｒ¹⁸は密着性基である。Ｒ¹⁹は酸不安定基である。Ｒ²⁰は単結合又は炭素数１〜１５の２価の有機基である。Ｒ²¹及びＲ²²は水素原子、メチル基又はトリフルオロメチル基である。）

(In the formula, R ¹⁷ is an alkyl group or a fluorinated alkyl group having 1 to 15 carbon atoms. R ¹⁸ is an adhesive group. R ¹⁹ is an acid labile group. R ²⁰ is a single bond or a carbon number. (It is a divalent organic group of 1 to 15. R ²¹ and R ²² are a hydrogen atom, a methyl group or a trifluoromethyl group.)

As the alkyl group having 1 to 15 carbon atoms and the fluorinated alkyl group having 1 to 15 carbon atoms of R ^17, the same groups as those described in the general formulas (4a) to (4f) can be used.

The adhesive group for R ¹⁸ is variously selected, and is particularly preferably a group exemplified by the following formula.

（上記式中、鎖線は結合手を示す。）

(In the above formula, the chain line indicates a bond.)

As the acid labile group for R ¹⁹ , those described for R ⁶ and R ⁷ can be used.
As the divalent organic group having 1 to 15 carbon atoms of R ²⁰ , those having a form in which one hydrogen atom in the already exemplified alkyl group is extracted (for example, methylene group or ethylene group) are used. A group exemplified by the formula can also be used.

（上記式中、鎖線は結合手を示す。）

(In the above formula, the chain line indicates a bond.)

（式中、Ｒ^31a〜Ｒ^31cは水素原子又はメチル基である。Ｒ³²は単結合、炭素数１〜４のアルキレン基、フェニレン基、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−ＮＨ−のいずれかである。Ｒ³³は単結合、炭素数１〜８の直鎖状、分岐状又は環状のアルキレン基のいずれかである。Ｒ^34a〜Ｒ^34d及びＲ^36a〜Ｒ^36cはそれぞれ独立に水素原子、炭素数１〜１２の直鎖状、分岐状又は環状のアルキル基、アルケニル基、オキソアルキル基又はオキソアルケニル基、炭素数６〜２０のアリール基、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のいずれかを示し、これらのうち水素原子の一部又は全部がアルコキシ基によって置換されていてもよく、Ｒ^34a〜Ｒ^34d及びＲ^36a〜Ｒ^36cの中に窒素原子、エーテル基、エステル基、ヒドロキシ基、又はカルボキシル基を含んでいてもよい。Ｒ^34a〜Ｒ^34d及びＲ^36a〜Ｒ^36cのうち２個は互いに結合してこれらが結合する窒素原子と共に環を形成することができ、その場合、環の形成に関与する基はそれぞれ独立に炭素数３〜１５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。Ｒ³⁵は炭素数１〜８の直鎖状、分岐状又は環状のアルキレン基を示す。Ｒ³⁷はカルボニル基、エステル基、エーテル基、又はハロゲン原子を有していてもよい炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基、又は、カルボニル基、エステル基、エーテル基、ハロゲン原子、炭素数１〜１５のアルキル基、又はフッ素化アルキル基を有していてもよい炭素数６〜１５のアリール基のいずれかを示す。Ｒ^38a及びＲ^38bは水素原子、又は炭素数１〜１５の直鎖状、分岐状又は環状のアルキル基であり、Ｒ^38a及びＲ^38bは結合してこれらが結合する炭素原子と共に環を形成することもできる。） The polymer compound of the present invention can exhibit sufficient performance even when used alone. However, a polymer compound having one or more repeating units represented by the following general formulas (5) to (7) for further imparting water repellency and water slidability, controlling alkali solubility and developer compatibility Can be used in a blend.

(In the formula, R ^{31a to} R ^31c are a hydrogen atom or a methyl group. R ³² is a single bond, an alkylene group having 1 to 4 carbon atoms, a phenylene group, —C (═O) —O—, —C (= O) -NH- R ³³ is a single bond or a linear, branched or cyclic alkylene group having 1 to 8 carbon atoms R ^{34a to} R ^34d and R ^{36a to} R ^36c is each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an alkenyl group, an oxoalkyl group or an oxoalkenyl group, an aryl group having 6 to 20 carbon atoms, Any one of 12 aralkyl groups or aryloxoalkyl groups, and some or all of the hydrogen atoms may be substituted with alkoxy groups, and R ^{34a to} R ^34d and R ^{36a to} R ^36c may be Nitrogen atom, ether group, ester group, hydroxy group Or two of which may contain a carboxyl group .R ^34a to R ^34d and R ^36a to R ^36c, taken together may form a ring together with the nitrogen atom to which they are attached, in which case, the ring The groups involved in the formation each independently represent an alkylene group having 3 to 15 carbon atoms, or a heteroaromatic ring having a nitrogen atom in the formula in the ring, R ³⁵ is a straight chain having 1 to 8 carbon atoms, R ³⁷ represents a branched or cyclic alkylene group, and R ³⁷ represents a carbonyl group, an ester group, an ether group, or a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms which may have a halogen atom, Or a carbonyl group, an ester group, an ether group, a halogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms which may have a fluorinated alkyl group. ^38a and R ^38b are hydrogen atoms, Or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, and R ^38a and R ^38b may be bonded to form a ring together with the carbon atom to which they are bonded.)

The alkylene group having 1 to 4 carbon atoms of R ³² includes one hydrogen atom among methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and tert-butyl group. The one with the shape extracted is used.

Examples of the linear, branched or cyclic alkylene group having 1 to 8 carbon atoms of R ³³ and R ³⁵ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, tert-butyl group, tert-amyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclohexylmethyl group, cyclohexylethyl group Among the groups, those in the form of extracting one hydrogen atom are used.

In the above formula (5), the ammonium salt (cation part) formed by R ^{34a to} R ^34d is obtained by neutralization reaction of the corresponding amine compound. In this case, the amine compound includes 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, amides, imides, carbamates, etc., and specifically, paragraph [0146] of JP-A-2008-111103. To [0164] are used.
R ^{36a to} R ^36c and R ³⁷ will be described in detail in the specific example of the general formula (6).
As the alkyl group having 1 to 15 carbon atoms of R ^38a and R ^39b, the same groups as those described in the general formulas (4a) to (4f) can be used.

Specific examples of the repeating unit of the general formula (5) include the following.

（式中、Ｒ^31a、Ｒ^34a〜Ｒ^34dは前記と同様である。）

(In the formula, R ^31a and R ^{34a to} R ^34d are the same as described above.)

Specific examples of the repeating unit of the general formula (6) include the following.

（式中、Ｒ^31bとＲ³⁷は前記と同様である。）

(In the formula, R ^31b and R ³⁷ are the same as described above.)

  Specific examples of the sulfonate used in the repeating unit of the general formula (6) include triflate, 1,1,1-trifluoroethanesulfonate, fluoroalkylsulfonate such as nonafluorobutanesulfonate, tosylate, benzenesulfonate, 4 -Fluorobenzene sulfonate, 1,2,3,4,5-pentafluorobenzene sulfonate, xylene sulfonic acid, dimethylene sulfonic acid, pt-butylbenzene sulfonic acid, naphthalene sulfonic acid, anthracene sulfonic acid, pyrene sulfonic acid, etc. Aryl sulfonate, mesylate, butane sulfonate, octane sulfonic acid, camphor sulfonic acid, adamantane sulfonic acid, norbornane sulfonic acid, cyclohexyl sulfonic acid, cyclopentane sulfonic acid, cyclobutane Acid, cyclopropane sulfonic acid, and alkyl sulfonates, such as dodecylbenzene sulfonic acid.

Specific examples of the repeating unit of the general formula (7) include the following, but are not limited thereto.

（式中、Ｒ^31cは前記と同様である。）

(Wherein R ^31c is the same as described above.)

  The polymer compound having a repeating unit represented by the above formulas (5) to (7) can exhibit sufficient performance only by a combination of the repeating units represented by the above formulas (5) to (7). In order to impart water repellency and water slidability, and control of alkali solubility and developer affinity, the aforementioned general formulas (8a) to (8e), (9a) to (9e), (10a) to (10c), It is also possible to comprise one or two or more repeating units represented by (11a) to (11c).

[Synthesis of polymerizable monomer compound]
The polymer compound of the present invention includes any repeating unit represented by the above formulas (1) to (3) as an essential unit. The polymerizable monomer compound corresponding to these repeating units is preferably produced by selecting an optimum method according to the structure of the compound. As an example, a production method by O-alkylation or O-acylation reaction of the corresponding hemiacetal compound is exemplified, but the production method is not limited to this method. Hereinafter, the synthesis of the acetal compound (1 ′) from the hemiacetal compound represented by the following general formula will be described in detail.

（式中、Ｘは一般式（Ｘ−１）〜（Ｘ−３）で表される構造を示す。Ｒ¹、Ｒ^2a、Ｒ^2b、Ｒ^3a、Ｒ^3b、Ｒ⁴、Ｒ^5a、Ｒ^5b、Ｒ^6a、Ｒ^6b、Ｒ^7a、Ｒ^7b、Ｒ^8a、Ｒ^8b、Ｒ^9a、Ｒ^9bは上述の通りである。）

(In the formula, X represents a structure represented by the general formulas (X-1) to (X-3). R ¹ , R ^2a , R ^2b , R ^3a , R ^3b , R ⁴ , R ^5a , R ^5b. R ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b are as described above.)

  The raw material hemiacetal compounds (X-1-H), (X-2-H), and (X-3-H) can be easily produced by a known method (see JP-A-2006-152255). .

  Reacting the hemiacetal compound represented by the above formula (X-1-H), (X-2-H), or (X-3-H) with an O-alkylating agent or an O-acylating agent. To synthesize an acetal compound (1 ′). Specific examples of the leaving group in the O-alkylating agent and the O-acylating agent include halogen atoms such as chlorine atom, bromine atom and iodine atom, alkanesulfonyloxy group such as methanesulfonyloxy group, p-toluenesulfonyloxy, etc. Examples thereof include arenesulfonyloxy groups such as a group. The amount of the O-alkylating agent or O-acylating agent used is desirably 0.3 to 10 mol, particularly 0.8 to 5 mol, with respect to 1 mol of the hemiacetal compound.

  The reaction can be carried out without solvent or in a solvent. Examples of the solvent include alcohols such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, and ethylene glycol, hydrocarbons such as hexane, heptane, benzene, toluene, and xylene, diethyl ether, dibutyl ether, tetrahydrofuran, 1,4- Non-protons such as ethers such as dioxane and diglyme, chlorinated solvents such as methylene chloride, chloroform and 1,2-dichloroethylene, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide and N-methylpyrrolidone Polar solvents, carboxylic acids such as formic acid and acetic acid, esters such as ethyl acetate and butyl acetate, ketones such as acetone and 2-butanone, nitriles such as acetonitrile, amines such as pyridine and triethylamine, and water Anti It can be used selectively to alone or in combination depending on the conditions.

The reaction temperature is selected in the range from −40 ° C. to the reflux temperature of the solvent depending on the reaction rate.
In order to increase the reaction rate, it is preferable to add a salt of a base or a transition metal to the reaction.
Examples of the base used in the reaction include amines such as pyridine, triethylamine, diisopropylethylamine, 4-dimethylaminopyridine, imidazole, alkoxy metals such as sodium methoxide, sodium ethoxide, potassium t-butoxide, sodium carbonate, potassium carbonate, Carbonates such as cesium carbonate, hydroxides such as sodium hydroxide, potassium hydroxide and tetramethylammonium hydroxide, metal hydrides such as sodium hydride and potassium hydride, organic such as butyl lithium and ethyl magnesium bromide The metal amides such as metals and lithium diisopropylamide may be selected depending on the reaction conditions and used alone or in combination. The amount of the base used is desirably 0.3 to 20 mol, particularly 0.8 to 10 mol, relative to 1 mol of the hemiacetal compound.

  The transition metal salt used in the reaction may be selected from lead carbonate, cadmium carbonate, silver carbonate, lead oxide, cadmium oxide, silver oxide, silver nitrate, etc. depending on the reaction conditions, and may be used alone or in combination. The base and the transition metal salt may be used alone or in combination. In addition, in order to improve the reaction rate, the reaction is performed by adding iodide such as sodium iodide, lithium iodide, tetrabutylammonium iodide, bromide such as sodium bromide, lithium bromide, tetrabutylammonium bromide. Also good. When the catalyst is added, the addition amount is preferably 0.001 to 2 mol, particularly 0.005 to 0.5 mol, per 1 mol of the hemiacetal compound.

  The reaction time is preferably about 0.1 to 100 hours, although it is desirable in terms of yield to follow the reaction by gas chromatography (GC) or thin layer chromatography (TLC) to complete the reaction. The desired acetal compound (1 ') is obtained from the reaction mixture by ordinary aqueous work-up. If necessary, compound (1 ') can be purified by conventional methods such as distillation, chromatography, recrystallization and the like. Alternatively, it may be possible to subject the salt generated in the reaction to filtration or to directly purify the reaction solution without performing an aqueous work-up. Here, the compound (1 ′) is taken as an example, but this synthesis method is also used for the production of the polymerizable monomer compounds (2 ′) and (3 ′) corresponding to the repeating units (2) and (3). Applicable.

[Synthesis of polymer compounds]
Hereinafter, the polymer compound containing the repeating units represented by the above formulas (1) to (3) and (4a) to (4f) is represented by the polymer compound (P1) and the above formulas (5) to (7). The polymer compound containing the repeating unit is referred to as a polymer compound (P2).

  When synthesizing the polymer compounds (P1) and (P2), radical polymerization using an initiator such as 2,2′-azobisisobutyronitrile (hereinafter abbreviated as AIBN), ion polymerization using alkyllithium or the like ( General polymerization techniques such as anionic polymerization) can be used, and these polymerizations can be carried out in accordance with conventional methods. Among these, it is preferable to synthesize the polymer compound used in the present invention by radical polymerization. In this case, the polymerization conditions are governed by the type and addition amount of the initiator, temperature, pressure, concentration, solvent, additive and the like.

  The radical polymerization initiator is not particularly limited, but examples include AIBN, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4- Dimethylvaleronitrile), 2,2′-azobis (2,4,4-trimethylpentane), azo compounds such as 2,2′-azobis (isobutyric acid) dimethyl, tert-butyl peroxypivalate, lauroyl peroxide Peroxide compounds such as benzoyl peroxide and tert-butyl peroxylaurate, water-soluble polymerization initiators such as potassium persulfate, and peroxides such as potassium persulfate and hydrogen peroxide and sodium sulfite. Examples thereof include a redox initiator composed of a combination of such reducing agents. The amount of the polymerization initiator used can be appropriately changed according to the type and polymerization conditions, but is usually 0.001 to 10 mol%, particularly 0.01 to 6 mol%, based on the total amount of monomers to be polymerized. Is adopted.

  When synthesizing the polymer compounds (P1) and (P2), a known chain transfer agent such as dodecyl mercaptan or 2-mercaptoethanol may be used in combination for adjusting the molecular weight. In that case, it is preferable that the addition amount of these chain transfer agents is 0.01-10 mol% with respect to the total number of moles of the monomer to polymerize.

  When synthesizing the polymer compound (P1), the general formulas (1) to (3), (4a) to (4f), (8a) to (8e), (9a) to (9e), (10a) to ( The polymerizable monomers corresponding to the repeating units represented by 10c) and (11a) to (11c) are mixed, and polymerization is carried out by adding the above-mentioned initiator and chain transfer agent. Similarly, when synthesizing the polymer compound (P2), the polymerizable monomers corresponding to the repeating units represented by the general formulas (5) to (7) are mixed, and the above-described initiator and chain transfer agent are added. Polymerization.

In the polymer compound (P1),
The total number of moles of monomers corresponding to the units of the general formulas (1) to (3) is U11,
The total number of moles of monomers corresponding to the units of the general formulas (4a) to (4f) is U12,
The total number of moles of monomers corresponding to the units of the general formulas (8a) to (8e), (9a) to (9e), (10a) to (10c), (11a) to (11c) is U13,
U11 + U12 + U13 = U1
If
0 <U11 / U1 <1, more preferably 0.1 ≦ U11 / U1 ≦ 0.7, still more preferably 0.2 ≦ U11 / U1 ≦ 0.6,
0 ≦ U12 / U1 <1, more preferably 0.3 ≦ U12 / U1 ≦ 0.9, still more preferably 0.4 ≦ U12 / U1A ≦ 0.8,
0 ≦ U13 / U1 <1, more preferably 0 ≦ U13 / U1 ≦ 0.5, still more preferably 0 ≦ U13 / U1 ≦ 0.3
It is. However, U1 ≦ 100 mol%.

In the polymer compound (P2),
The total number of moles of the monomer corresponding to the unit of the general formula (5) is U21,
The total number of moles of the monomer corresponding to the unit of the general formula (6) is U22,
The total number of moles of the monomer corresponding to the unit of the general formula (7) is U23,
The total number of moles of monomers corresponding to the units of the general formulas (8a) to (8e), (9a) to (9e), (10a) to (10c), (11a) to (11c) is U24,
U21 + U22 + U23 + U24 = U2
If
0 ≦ U21 / U2 <1, more preferably 0 ≦ U21 / U2 ≦ 0.5, still more preferably 0 ≦ U21 / U2 ≦ 0.3,
0 ≦ U22 / U2 <1, more preferably 0 ≦ U22 / U2 ≦ 0.5, still more preferably 0 ≦ U22 / U2 ≦ 0.3,
0 <U23 / U2 <1, more preferably 0.5 ≦ U23 / U2 <1, more preferably 0.7 ≦ U23 / U2 <1
0 ≦ U24 / U2 <1, more preferably 0 ≦ U24 / U2 <0.5, still more preferably 0 ≦ U24 / U2 <0.3
It is. However, U2 ≦ 100 mol%.

  When performing the polymerization, a solvent may be used as necessary. As the polymerization solvent, those that do not inhibit the polymerization reaction are preferable, and typical examples include esters such as ethyl acetate, n-butyl acetate, and γ-butyrolactone, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, toluene, Aliphatic or aromatic hydrocarbons such as xylene and cyclohexane, alcohols such as isopropyl alcohol and ethylene glycol monomethyl ether, and ether solvents such as diethyl ether, dioxane and tetrahydrofuran can be used. These solvents may be used alone or in combination of two or more. The amount of the polymerization solvent used can be appropriately changed according to the polymerization conditions such as the target degree of polymerization (molecular weight), the amount of initiator added, and the polymerization temperature. Usually, the concentration of the monomer to be polymerized is 0.1. A solvent is added so that it may be -95 mass%, especially 5-90 mass%.

  The reaction temperature of the polymerization reaction is appropriately changed depending on the kind of the polymerization initiator or the boiling point of the solvent, but is usually preferably 20 to 200 ° C, particularly preferably 50 to 140 ° C. The reaction vessel used for such a polymerization reaction is not particularly limited.

  Any known method can be used as a method for removing the organic solvent or water as a medium from the polymer solution or dispersion thus obtained. For example, reprecipitation filtration or reduced pressure can be used. There are methods such as heating distilling at

  In the case of the polymer compounds (P1) and (P2), if the weight average molecular weight (Mw) is too small, mixing with the resist material and dissolution in water are likely to occur. On the other hand, if the weight average molecular weight is too large, there may be a problem in film formability after spin coating, or the alkali solubility may be lowered. From that viewpoint, the polystyrene-reduced weight average molecular weight by gel permeation chromatography (GPC) is 1,000 to 500,000, preferably 2,000 to 30,000.

In the polymer compounds (P1) and (P2), R ⁴ in the above formula (1), R ¹⁴ in the above formulas (4a), (4b) and (4e), R ^{19 in the} above formulas (8c) and (9c). Can also be introduced by a post-protection reaction. That is, after polymerizing R ⁴ , R ¹⁴ and R ¹⁹ with a hydrogen monomer in advance to synthesize a polymer compound, a part or all of the hydroxyl groups of the polymer obtained by the post-protection reaction as shown in the following formula ⁴ , R ¹⁴ and R ¹⁹ (wherein R ⁴ , R ¹⁴ and R ¹⁹ are the same as above).

In the post-protection reaction, after 1 to 2 equivalents of the base is reacted with the polymer compound with respect to the target value of the substitution rate of the hydroxyl group, 1 to 2 equivalents of R—X (R is R ⁴ or R described above) with respect to the base. ¹⁴ and R ¹⁹ , X can be reacted with chlorine, bromine, or iodine to obtain the desired post-protected polymer compound.

  The solvent used in the post-protection reaction is selected from hydrocarbons such as benzene and toluene, ethers such as dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane alone or 2 A mixture of more than one can be used. Examples of the base include, but are not limited to, sodium hydride, n-butyllithium, lithium diisopropylamide, triethylamine, pyridine and the like.

  In the polymer compound (P2), the ammonium salt in the repeating unit of the general formula (5) is represented by a neutralization reaction between a (meth) acrylate having a sulfo group in the side chain and a corresponding amine, or the following general formula: It can be obtained by an ion exchange reaction with an ammonium salt.

（式中、Ｒ^34a〜Ｒ^34dは前記と同様であり、Ｌ^-はＯＨ^-、Ｃｌ^-、Ｂｒ^-、Ｉ^-、Ｒ³⁹ＣＯ₂ ^-、又はＮＯ₃ ^-である。Ｒ³⁹は水素原子又は一価の有機基を示す。）

(Wherein R ^{34a to} R ^34d are the same as defined above, and L ⁻ represents OH ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , R ³⁹ CO ₂ ⁻ , or NO ₃ ⁻ . R ³⁹ represents a hydrogen atom or Indicates a monovalent organic group.)

  In the polymer compound (P2), when the repeating unit of the above formula (5) is introduced, the above-described neutralization reaction or ion exchange reaction can be performed at the monomer stage, or can be performed after polymer synthesis. is there. However, when the above reaction is performed after polymer synthesis, if the amount of amine added is small, an amine salt is not uniformly formed in the polymer unit, which may cause local bridge defects during pattern formation. In order to avoid such a situation, it is preferable to perform polymerization using a monomer in which a sulfonic acid amine salt is uniformly distributed by performing a neutralization reaction or an ion exchange reaction in the state of the monomer.

  In the polymer compound (P2), when the repeating unit of the above formula (6) is introduced, for those containing a tertiary or lower ammonium salt, (meth) acrylate having an amino group in the side chain and the corresponding sulfonic acid Can be obtained by a neutralization reaction. Moreover, what contains a quaternary ammonium salt can be obtained by the same ion exchange reaction as the above-mentioned. As in the case of the repeating unit of the above formula (5), the above-described neutralization reaction and ion exchange reaction can be performed at the monomer stage or after the polymer synthesis.

  In the repeating unit of the above formula (5), the amount of neutralization of the sulfo group and amine compound in the whole polymer may have a small amine equivalent and a sulfonic acid residue, and vice versa. Good. When there is a sulfonic acid residue, there is an effect of preventing a bridge between resist patterns after development when combined with a photoresist, whereas when there is an excess of amine, there is an effect of improving the rectangularity of the resist pattern. Based on this, the amount of sulfo group and amine can be adjusted as appropriate while observing the resist pattern after development. The same applies to the repeating unit of the general formula (6).

[Adjustment of resist protective film material]
In the resist protective film material of the present invention, the polymer compound (P1) includes a structure in which the hydroxyl group of the fluorine-containing hemiacetal is protected in the repeating unit of any one of the general formulas (1) to (3), and the resin structure By selecting one of these, various performances such as water repellency, water slidability, fat solubility, acid decomposability, hydrolyzability, and alkali solubility can be adjusted.

  Further, since the polymer compound (P2) contains a hydrophilic sulfonic acid amine salt in the repeating unit, the polymer is easily oriented to the resist side after spin coating. As a result, the resist surface after development becomes hydrophilic, and blob defects can be suppressed. When a polymer having only a sulfo group is used as the protective film material, a part of the quencher in the resist film moves to the protective film layer. When the quencher moves, the quencher concentration on the outermost surface of the resist film is lowered, and accordingly, the resist pattern after development is reduced, and as a result, the etching resistance may be lowered. On the other hand, since the polymer compound (P2) has a sulfonic acid amine salt in the protective film layer, the quencher does not move as described above, and a rectangular resist pattern can be obtained.

  When the polymer compounds (P1) and (P2) are mixed and used, both cause layer separation at the time of spin coating, the polymer compound (P1) having excellent water repellency and water slidability on the upper layer of the protective film, and the upper part of the resist film ( The hydrophilic polymer compound (P2) is localized in the lower layer of the protective film. As a result, it is possible to realize a resist protective film that not only improves the water repellency and water sliding performance of the resist surface but also suppresses blob defects.

  When the polymer compound (P1) and the polymer compound (P2) are blended and used, the mixing ratio is arbitrary, and the mass ratio of the polymer compound (P1) to the whole resin is 5 to 95%, preferably 20 to The range can be 93%, more preferably 30 to 90%.

  In the resist protective film material of the present invention, the polymer compounds (P1) and (P2) can be preferably used, but the mechanical properties, thermal properties, alkali solubility, water repellency, water slide performance, Other polymer compounds can be mixed for the purpose of changing physical properties. At that time, the range of the polymer compound to be mixed is not particularly limited, but can be mixed with a known polymer compound or the like for resist protective film use in an arbitrary range.

  The resist protective film material of the present invention is preferably used by dissolving the polymer compound in a solvent. In this case, it is preferable to use a solvent so that the density | concentration of the said whole resin will be 0.1-20 mass%, especially 0.5-10 mass% from the point of the film-forming property by a spin coating method.

  The solvent used is not particularly limited, but a solvent that does not dissolve the resist layer is preferably used. Examples of the solvent that does not dissolve the resist layer include higher polar alcohols having 4 or more carbon atoms, nonpolar solvents such as toluene, xylene, anisole, hexane, cyclohexane, decane, and ether compounds. In particular, higher alcohols having 4 or more carbon atoms and ether compounds 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-pe Tanol, 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, and the like. These can be used alone or in admixture of two or more. It is not limited.

  On the other hand, a fluorine-based solvent can be preferably used because it does not dissolve the resist layer. 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 perfluoro Octanoate, 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- Methyl-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 , 1H, 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-per Fluorooctanol, 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, perfluorotripenti Amine, 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, trifluoro Methyl 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 two or more can be used in combination. However, it is not limited to these.

  In the resist protective film material of the present invention, performance improvement such as correction of pattern shape can be performed using a basic compound. For example, in the case of the polymer compound (P1), since the repeating unit has an acidic hydroxyl group, a part of the quencher in the resist film may move to the protective film layer. As described above, when the quencher moves, the quencher concentration on the outermost surface of the resist is lowered and the resist pattern after development is reduced. In order to avoid such movement of the quencher, a basic compound can be added in advance to the resist protective film material to prevent deterioration of the pattern shape.

  Here, a nitrogen-containing organic compound is suitable as the basic compound, and one or more nitrogen-containing organic compounds can be blended and used. Such nitrogen-containing organic compounds include primary, secondary and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, sulfonyl Nitrogen-containing compounds having a group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, amides, imides, carbamates and the like. Specific examples thereof include those described in JP-A-2008-111103. It is described in paragraphs [0149] to [0163]. The amount of the basic compound used is preferably 0.001 to 2 parts by mass, particularly 0.01 to 1 part by mass with respect to 100 parts by mass of the polymer compound (base resin).

[Pattern formation method]
In the pattern forming method of the present invention, at least a step of forming a photoresist film on the 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 are performed. It is preferable to include a step and a step of developing using a developer.

  In the case of forming a resist protective film, a resist protective film material solution is spin-coated on the pre-baked photoresist film, and is applied on a hot plate at 50 to 150 ° C. for 1 to 10 minutes, preferably 70 to 140 ° C., 1 to 5 Pre-baked for a minute to form a resist protective film. The film thickness is preferably in the range of 10 to 500 nm.

  When a resist film protective film is applied after the resist film surface is previously applied with a solvent during spin coating, the amount of dispense of the protective film material can be reduced. At that time, as a method of coating the resist film surface, a spin coating method and a vapor prime method can be mentioned, but a spin coating method is generally used, and a solvent to be used is a higher alcohol that does not dissolve the resist film, It can be selected from ether solvents and fluorine solvents.

In the exposure step, a mask for forming a target pattern is placed over the photoresist film, and high energy rays such as deep ultraviolet rays, excimer laser, and X-rays or electron beams are applied in an exposure amount of 1 to 200 mJ / cm ² , preferably Is irradiated so as to be 10 to 100 mJ / cm ² . At this time, immersion exposure performed by inserting a liquid between the resist protective film and the projection lens is preferable, but the exposure is not particularly limited, and dry exposure in an air or nitrogen atmosphere may be used. , Exposure in a vacuum such as EUV may be used. In the case of immersion exposure, an exposure wavelength light source in the range of 180 to 250 nm is preferable, and water is preferably used as the liquid inserted between the protective film and the lens.

  In immersion exposure, the presence or absence of cleaning of the wafer edge and back surface and the cleaning method are important in order to prevent water from flowing into the back surface of the wafer and elution from the substrate. For example, the solvent may be volatilized by baking the resist protective film in the range of 40 to 130 ° C. for 10 to 300 seconds after spin coating. In addition, edge cleaning performed at the time of forming a resist film by dry exposure may not be preferable for immersion exposure because water may remain on the edge portion of the hydrophilic substrate surface. Therefore, edge cleaning may not be performed during spin coating of the resist protective film.

  After exposure, post-exposure baking (PEB) is performed on a hot plate at 60 to 150 ° C. for 1 to 5 minutes, preferably 80 to 140 ° C. for 1 to 3 minutes. When PEB is performed, if water remains on the resist protective film, water may pass through the protective film in PEB. As a result, the acid in the resist may be sucked out and pattern formation may not be possible. In order to avoid this, it is necessary to completely remove water on the protective film before PEB. Examples of the method include a spin dry method, a method of purging the protective film surface with dry air or nitrogen, a shape of the water recovery nozzle on the stage, and optimization of the water recovery process. In addition, designing and using a material excellent in water repellency and water slidability such as the protective film material of the present invention is also effective for water separation.

  After performing PEB, 0.1 to 5% by mass, preferably 2 to 3% by mass of a developer of an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) is used for 10 to 300 seconds, preferably 0.8%. Development is performed for 5 to 2 minutes by a conventional method such as a dip method, a paddle method, or a spray method. As the alkali developer, a 2.38 mass% tetramethylammonium hydroxide aqueous solution is generally widely used. When the resist protective film material of the present invention is used, since the protective film material itself exhibits alkali solubility, the resist protective film can be peeled off simultaneously with development.

  In the pattern forming method using the resist protective film material of the present invention, the lower layer resist material is not particularly limited. The type of resist may be either positive or negative. Further, it may be a normal hydrocarbon-based single-layer resist material or a two-layer (multi-layer) resist material containing silicon atoms or the like.

  The resist material used in KrF exposure is a polyhydroxystyrene or polyhydroxystyrene- (meth) acrylate copolymer as a base resin, in which a part or all of the hydrogen atoms of hydroxy groups or carboxyl groups are substituted with acid labile groups. Coalescence is preferably used.

  The resist material in ArF exposure preferably has a structure that does not contain an aromatic as a base resin. Specifically, a copolymer of (meth) acrylic acid derivative, an alternating copolymer of norbornene derivative and maleic anhydride, norbornene derivative, anhydrous Maleic acid, copolymer of (meth) acrylic acid derivative, alternating copolymer of tetracyclododecene derivative and maleic anhydride, tetracyclododecene derivative, maleic anhydride, copolymer of (meth) acrylic acid derivative, Alternating copolymer of norbornene derivative and maleimide derivative, norbornene derivative, maleimide derivative, copolymer of (meth) acrylic acid derivative, alternating polymer of tetracyclododecene derivative and maleimide derivative, tetracyclododecene derivative, maleimide derivative, Copolymer of (meth) acrylic acid derivative, polynorbol One or more polymer compounds selected from the emissions derivatives and metathesis ring-opening polymers are preferably used.

  Since a material containing an aromatic ring in a repeating unit has absorption at a wavelength of 193 nm, it could not be used as an ArF resist at first, but the influence of absorption is reduced as the resist film is thinned, and its application is examined. It has become like this. Further, when the NA of the projection lens exceeds 1, reflection from the substrate due to obliquely incident light increases, so it has been proposed to actively use an aromatic ring having absorption to suppress reflection from the substrate. In this case, hydroxy vinyl naphthalene, methacrylate containing naphthalene or naphthol skeleton in the side chain, fluorinated hydroxy styrene, fluoroalkyl hydroxy styrene, fluorinated styrene, fluoroalkyl styrene, hexafluoroisopropanol styrene, hexafluoroisopropanol indene, etc. Can be used.

The resist protective film material of the present invention can also be applied to a pattern forming method for mask blanks. That is, after applying a photoresist on a mask blank substrate such as SiO ₂ , Cr, CrO, CrN, or MoSi, a resist protective film is formed on the upper layer using the resist protective film material of the present invention. At this time, an SOG film and an organic underlayer film may be formed between the photoresist and the blank substrate to form a three-layer structure. After forming a resist protective film, it is exposed with an electron beam in a vacuum using an electron beam drawing machine, post-exposure bake (PEB) is performed after exposure, and development is performed with an alkali developer for 10 to 300 seconds. Form a pattern.

  As a resist material for mask blanks, novolak, hydroxystyrene or the like is mainly used as a base resin. Those in which an alkali-soluble hydroxyl group in these resins is substituted with an acid labile group are used as a positive type, and those obtained by adding a crosslinking agent are used as a negative type. Specifically, hydroxystyrene and (meth) acryl derivatives, styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, hydroxyvinylnaphthalene, hydroxyvinylanthracene, indene, hydroxyindene, acenaphthylene, norbornadiene, coumarone, chromone, etc. were copolymerized. A polymer compound is preferably used.

  Hereinafter, the present invention will be specifically described with reference to synthesis examples, examples and comparative examples, but the present invention is not limited to the following examples. In the examples, “GPC” refers to gel permeation chromatography, and the weight average molecular weight (Mw) and number average molecular weight (Mn) of the obtained polymer compound are measured by GPC as polystyrene conversion values. did.

[Monomer Synthesis Example 1] Synthesis of Monomer 1

  A mixture of 50.0 g of raw material hemiacetal, 40.8 g of pyridine, and 100 g of acetonitrile was stirred in an ice-cooled, nitrogen atmosphere, and 22.0 g of isobutyric chloride was added dropwise over 30 minutes. After 30 minutes, 100 g of hexane was added for dilution, followed by addition of 400 g of water and stirring for 30 minutes to stop the reaction and decompose excess reagent. After normal aqueous work-up, purification was performed by distillation under reduced pressure to obtain 60.8 g of the desired product (yield 98%). Colorless liquid, boiling point: 63-67 ° C./13 Pa. In NMR analysis, this was a diastereomeric mixture with a molar ratio of 67:33.

IR (thin film): ν = 2981, 2940, 2883, 1774, 1727, 1639, 1471, 1452, 1388, 1336, 1303, 1282, 1218, 1155, 1112, 1081, 1039, 1004, 939, 927 cm ⁻¹ .
¹ H-NMR (300 MHz, in DMSO-d6), diastereomeric mixture with a molar ratio of 67:33: δ = 1.11 (0.99 H, d, J = 6.9 Hz), 1.12 (0.99 H, d , J = 7.1 Hz), 1.14 (4.02H, d, J = 6.9 Hz), 1.66-1.70 (3H, m), 1.85-1.90 (3H, m) 2.70 (0.33H, qq, J = 7.1, 6.9 Hz), 2.74 (0.67H, sep, J = 6.9 Hz), 4.65 (0.67H, br.d) , J = 11.1 Hz), 4.68 (0.33H, dd, J = 9.8, 1.5 Hz), 4.79 (0.33H, br.d, J = 9.8 Hz). 85 (0.67H, dd, J = 11.1, 2.7 Hz), 5.80 (0.67H, m), 5.82 (0.33H, m), 6.08 ( 0.67H, m), 6.09 (0.33H, m) ppm.
¹⁹ F-NMR (283 MHz, in DMSO-d6), diastereomeric mixture at a molar ratio of 67:33: δ = −124.32 (0.67 F, dq, J = 250, 17 Hz), −119.75 (0.33 F) , Dqd, J = 246, 17.4 Hz), −110.80 (0.33 F, d, J = 246 Hz), −109.49 (0.67 F, d, J = 250 Hz), −80.19 (0 .67F, d, J = 17 Hz), −79.92 (0.33 F, d, J = 17 Hz) ppm.

[Monomer Synthesis Example 2] Synthesis of Monomer 2

  Monomer 2 was synthesized by a method according to [Monomer Synthesis Example 1] except that isovaleric acid chloride was used instead of isobutyric acid chloride.

Colorless liquid, boiling point: 70 ° C./13 Pa.
IR (thin film): ν = 2966, 2935, 2877, 1779, 1727, 1639, 1469, 1452, 1386, 1371, 1336, 1301, 1282, 1216, 1155, 1110, 1087, 1039, 1004, 946, 927 cm ⁻¹ .
¹ H-NMR (600 MHz, in DMSO-d6), diastereomeric mixture with a molar ratio of 65:35: δ = 0.89 (1.05 H, d, J = 6.4 Hz), 0.90 (1.05 H, d , J = 6.4 Hz), 0.92 (1.95 H, d, J = 6.4 Hz), 0.92 (1.95 H, d, J = 6.4 Hz), 1.66 (1.05 H, br.d, J = 3.7 Hz), 1.68 (1.95 H, br.d, J = 3.2 Hz), 1.86 (1.95 H, m), 1.87 (1.05 H, m) ) 1.90-2.05 (1H, m), 2.31 (0.35H, dd, J = 15.6, 7.3 Hz), 2.36 (0.65H, dd, J = 15. 5, 6.8 Hz), 2.37 (0.35 Hz, dd, J = 15.6, 6.4 Hz), 2.40 (0.65 H, dd, J = 15.5, 6.9 Hz), 4.63 (0.65 H, br.d, J = 11.0 Hz), 4.66 (0.35 H, dd, J = 10.1, 1.0 Hz), 4.77 (0 .35H, br.d, J = 10.1 Hz), 4.83 (0.65H, dd, J = 11.0, 2.3 Hz), 5.78 (0.65H, m), 5.81 ( 0.35H, m), 6.06 (0.65H, m), 6.08 (0.35H, m) ppm.
¹⁹ F-NMR (565 MHz, in DMSO-d6), diastereomeric mixture of 65:35 molar ratio: δ = −124.06 (0.65 F, dq, J = 249, 16 Hz), −119.57 (0.35 F) , Dqd, J = 246, 17.3 Hz), −11.46 (0.35 F, d, J = 246 Hz), −108.98 (0.65 F, d, J = 249 Hz), −79.90 (0 .65F, d, J = 16 Hz), −79.57 (0.35 F, d, J = 18 Hz) ppm.

[Monomer Synthesis Example 3] Synthesis of Monomer 3

  Monomer 3 was synthesized by the method according to [Example 1] except that triethylamine was used instead of pyridine and 1-chloro-1-methoxy-2-methylpropane and sodium iodide were used instead of isobutyric chloride.

Colorless liquid, boiling point: 70 ° C./27 Pa.
IR (thin film): ν = 2969, 2881, 2848, 1727, 1639, 1473, 1452, 1388, 1367, 1328, 1303, 1284, 1207, 1159, 1103, 1066, 1010, 970, 946 cm ⁻¹ .
¹ H-NMR (600 MHz, in DMSO-d6), a mixture of four diastereomers in a molar ratio of 33: 32: 19: 16: δ = 0.80-0.90 (6H, m), 1.61-1.71 (3H, m), 1.84-1.95 (4H, m), 3.20 (0.16H, s), 3.26 (0.19H, s), 3.30 (0.33H, s) ), 3.34 (0.32H, s), 4.35-4.80 (2H, m), 5.72-5.82 (1H, m), 6.05-6.10 (1H, m) ) Ppm.
¹⁹ F-NMR (565 MHz, in DMSO-d6), a mixture of four diastereomers in a molar ratio of 33: 32: 19: 16: δ = 124.63 (0.33 F, dq, J = 243, 19 Hz), −124 .30 (0.32F, dq, J = 236, 18 Hz), −121.63 (0.32F, d, J = 236 Hz), −121.49 (0.16F, d, J = 241 Hz), −120 .52 (0.16F, dq, J = 241, 17 Hz), −119.38 (0.19F, dq, J = 245, 21 Hz), 116.83 (0.19F, d, J = 245 Hz), − 114.83 (0.33F, d, J = 243 Hz), −79.00 (0.19F, d, J = 21 Hz), −78.76 (0.33F, d, J = 20 Hz), −78. 29 (0.16F, d, J = 1 Hz), - 78.23 (0.32F, d, J = 20Hz) ppm.

[Example of polymer synthesis]
The structural formulas of the polymerizable monomer (Monomers 1 to 16) and amine (Base 1) used in the polymer synthesis examples are shown below.

[Polymer Synthesis Example 1] Copolymerization of Monomer 1 and Monomer 6 (20/80)
A monomer solution was prepared by charging 23.41 g of Monomer 1, 77.11 g of Monomer 6, 3.75 g of 2,2′-azobis (isobutyric acid) dimethyl and 100.1 g of methyl ethyl ketone into a flask under a nitrogen atmosphere. The solution temperature was 20 to 25 ° C. 50.1 g of methyl ethyl ketone was put into another flask under a nitrogen atmosphere, heated to 80 ° C. with stirring, and then the monomer solution was added dropwise over 4 hours. After completion of the dropping, stirring was continued for 2 hours while maintaining the temperature of the polymerization solution at 80 ° C., and after completion of the aging, the solution was cooled to room temperature. After adding 200 g of toluene to the flask, the reaction mixture was concentrated using an evaporator until the total weight of the reaction mixture became 250 g. This concentrated solution was dropped into 1,500 g of hexane, and the precipitated copolymer was separated and then washed with 600 g of hexane to separate a white solid. The white solid was vacuum-dried at 50 ° C. for 20 hours to obtain 69.3 g of the target polymer compound (Polymer 2). As a result of analyzing the composition of the resin by ¹ H-NMR, the composition ratio of Monomer 1 and Monomer 6 in the copolymer was 19/81 mol%.

[Polymer synthesis examples 2 to 19]
The above-mentioned polymerizable monomers (Monomers 1 to 13) were charged with the compositions shown in Tables 1 to 5, and Polymers 1 to 19 were synthesized using the same formulation as the synthesis of Polymer 2.

[Polymer Synthesis Example 20] Copolymerization of Monomer 6 and Monomer 14 in the presence of Base 1 (90/10)
96.46g Monomer 6, 4.03g Monomer 14, 1.87g Base 1, 4.18g 2,2'-azobis (isobutyric acid) dimethyl, 155, 56g isopropyl alcohol were charged into a flask under nitrogen atmosphere. A monomer solution was prepared, and the solution temperature was set to 20 to 25 ° C. 77.78 g of isopropyl alcohol was added to another flask under a nitrogen atmosphere, heated to 80 ° C. with stirring, and then the monomer solution was added dropwise over 4 hours. After completion of the dropping, stirring was continued for 2 hours while maintaining the temperature of the polymerization solution at 80 ° C., and after completion of the aging, the solution was cooled to room temperature. Into the obtained polymerization solution, 300 g of 2-propanol was added, followed by washing with 300 g of ultrapure water three times. The organic layer was extracted, concentrated using an evaporator until the total amount became 200 g, and then crystallized with 1,500 g of hexane. The precipitated copolymer was separated and washed with 600 g of hexane to separate a white solid. The white solid was vacuum-dried at 50 ° C. for 20 hours to obtain 79.8 g of the target polymer compound (Polymer 20). The composition of the resin was analyzed by ¹ H-NMR. As a result, the composition ratio of Monomer 6, Monomer 14, Monomer 14 and Base 1 salt (see the following formula) in the copolymer was 89/9/2 mol%.

[Polymer Synthesis Example 21] Copolymerization of Monomer 6 and Monomer 15 in the presence of Base 1 (90/10)
Polymerization was performed using Monomer 6, Monomer 15, and Base 1 with the same formulation as the synthesis of Polymer 20, to obtain 75.3 g of the target polymer compound (Polymer 21). As a result of analyzing the composition of the resin by ¹ H-NMR, the composition ratio of Monomer 6, Monomer 15, Monomer 15 and the salt of Base 1 (see the following formula) in the copolymer was 90/8/2 mol%.

[Polymer Synthesis Example 22] Copolymerization of Monomer 6 and Monomer 16 (90/10)
Polymerization was carried out using Monomer 6 and Monomer 16 with the same formulation as the synthesis of Polymer 20, to obtain 81.5 g of the target polymer compound (Polymer 22). As a result of analyzing the composition of the resin by ¹ H-NMR, the composition ratio of Monomer 6 and Monomer 16 in the copolymer was 90/10 mol%.

[Comparative Polymer Synthesis Example 1] Monomer 6 homopolymer synthesis 100.0 g of Monomer 6, 3.91 g of 2,2′-azobis (isobutyric acid) dimethyl, 100.0 g of isopropyl alcohol were charged into a flask under a nitrogen atmosphere. A monomer solution was prepared, and the solution temperature was set to 20 to 25 ° C. 50.0 g of isopropyl alcohol was added to another flask under a nitrogen atmosphere, heated to 80 ° C. with stirring, and then the monomer solution was added dropwise over 4 hours. After completion of the dropwise addition, stirring was continued for 3 hours while maintaining the temperature of the polymerization solution at 80 ° C., and the mixture was cooled to room temperature after completion of aging. The obtained polymerization solution was dropped into 2,000 g of water, and the precipitated copolymer was separated by filtration. The obtained copolymer was washed 4 times with 600 g of a mixed solution of hexane / isopropyl ether (9/1) to separate a white solid. The white solid was vacuum-dried at 50 ° C. for 20 hours to obtain 92.8 g of the target polymer compound (Comparative Polymer 1). As a result of GPC measurement of the obtained copolymer, the weight average molecular weight (Mw) was 7,800 in terms of polystyrene, and the dispersity (Mw / Mn) was 1.6.

[Evaluation example using resist protective film]
Polymers 1 to 22 and Comparative Polymer 1 (1.0 g) were dissolved in a mixed solvent of diisopentyl ether (23 g) and 2-methyl-1-butanol (2 g) at a mixing ratio shown in Table 6 and filtered through a 0.2 μm size polypropylene filter. Then, a resist protective film solution was prepared (TC-1 to 27, comparative TC-1 to 2).

  The obtained resist protective film solution was spin-coated on a silicon substrate, baked at 100 ° C. for 60 seconds, and then a 50 nm-thick resist protective film (TC-1 to 27, comparative TC-1 to 2) was produced. Then, using the wafer coated with this protective film, (1) refractive index measurement (wavelength 193 nm) by spectroscopic ellipsometry (manufactured by JA Woollam Co., Ltd.), (2) pure water rinse (5 minutes) (3) Film thickness fluctuation after development with 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, (4) Tilt method contact angle meter Drop Master 500 (Kyowa Interface Science Co., Ltd.) The fall angle and the receding contact angle were measured using The results are shown in Table 6.

  From Table 6, it can be seen that the polymer compound (P1) has a receding contact angle higher than that of the comparative polymer. In addition, when the polymer compound (P1) and the polymer compound (P2) are used in a blend, the value of the receding contact angle is almost the same as that of the polymer compound (P1) alone. It can be seen that the polymer compound (P1) is present in the upper layer of the polymer compound (P2). In general, the lower the falling angle, the easier the water on the protective film flows, and the higher the receding contact angle, the more difficult the droplets remain even at high-speed scanning exposure. Then, it turns out that the performance of a fall angle | corner and receding contact angle is superior to comparison TC-1 or TC-2.

[Example of resist evaluation]
Resist Polymer shown below 5g, PAG1 0.5g, Quencher1 0.1g, dissolved in 100g propylene glycol monoethyl ether acetate (PGMEA), filtered through a 0.2μm size polypropylene filter, resist A solution was made.

  Next, an antireflection film ARC-29A (manufactured by Nissan Chemical Industries, Ltd.) is formed on a silicon substrate (film thickness is 87 nm), and the resist solution is applied thereon and baked at 105 ° C. for 60 seconds. Thus, a resist film having a thickness of 120 nm was produced. The above-mentioned resist protective film was applied thereon and baked at 100 ° C. for 60 seconds. In order to reproduce the simulated immersion exposure, the exposed film was rinsed with pure water for 5 minutes, and then ArF scanner S307E (Nikon Corporation, NA 0.85, σ 0.93 / 0.62, 20 degree dipole illumination) , 6% halftone phase shift mask), rinse with pure water for 5 minutes, post-exposure bake (PEB) at 100 ° C for 60 seconds, 2.38 mass% TMAH development Development was performed with the solution for 60 seconds. Moreover, the process of exposure-pure water rinse-PEB-development was also performed without the protective film. Then, the obtained wafer was cleaved, and the pattern shape and sensitivity of 65 nm line and space were compared. Furthermore, 5 μl of water droplets were dropped on the developed resist film, and the contact angle between the resist interface and the water droplet interface was measured. These results are summarized in Table 7.

  When pure water rinse was performed after exposure without a protective film, the pattern shape became T-top shape. This is probably because the generated acid was dissolved in water. On the other hand, the protective film material of the present invention had a high receding contact angle, and not only the contact angle of the resist after development was reduced, but also the resist pattern after development was rectangular.

  In the case of the resist protective film material of the present invention, the polymer compound (P1) alone has a high receding contact angle but a large water contact angle after development. On the other hand, the polymer compound (P2) having a sulfonic acid amine salt is inferior in water repellency and water slidability, but has a low water contact angle after development and a rectangular resist pattern. And it was found that by blending both, a protective film material having a high receding contact angle and a low water contact angle after development can be obtained.

  Next, the resist protective film (TC-21 and comparison TC-2) used in the above-mentioned exposure experiment was microfiltered with a high density polyethylene filter of 0.02 μm size. After forming an antireflection film ARC-29A (Nissan Chemical Industry Co., Ltd.) on an 8-inch silicon substrate (film thickness is 87 nm), a resist solution is applied thereon and baked at 105 ° C. for 60 seconds. A resist film having a thickness of 120 nm was produced. A resist protective film was applied thereon and baked at 100 ° C. for 60 seconds. After performing a checkered flag exposure in which an exposed area and an unexposed area of an open frame are exposed alternately with an area of 20 mm square on the entire surface of the wafer with an ArF scanner S307E (manufactured by Nikon Corporation, NA 0.85 σ 0.93, Cr mask). Then, post-exposure baking (PEB) was performed, and development was performed for 60 seconds with a 2.38 mass% TMAH developer. The number of defects in the unexposed portion of the checker flag was measured at a pixel size of 0.125 μm using a defect inspection apparatus WinWin-50-1200 (manufactured by Tokyo Seimitsu Co., Ltd.). A defect generated on the resist surface in the unexposed portion is a spot-like defect and is classified as a blob defect. The results are shown in Table 8. From this result, it can be seen that the resist protective film material blended with the polymer compound (P1) and the polymer compound (P2) has fewer defects than the protective film material of the comparative example.

[Example of electron beam exposure]
In the evaluation of electron beam drawing, the following EB Polymer (90 parts by mass) synthesized by radical polymerization, PAG2 (10 parts by mass) and Quencher2 (0.4 parts by mass) were mixed with propylene glycol monomethyl ether acetate (PGMEA, 700 parts by mass). ) And ethyl lactate (EL, 300 parts by mass), and then filtered through a 0.2 μm size filter to prepare a positive resist material.

The obtained positive resist material was spin-coated on a Si substrate having a diameter of 6 inches (150 mm) using a clean track Mark 5 (manufactured by Tokyo Electron Ltd.) and pre-baked on a hot plate at 110 ° C. for 60 seconds to have a thickness of 200 nm. A resist film was prepared. Using this wafer, drawing in a vacuum chamber was performed at an HV voltage of 50 keV using HL-800D (manufactured by Hitachi, Ltd.). Thereafter, the sample was left in a vacuum chamber for 20 hours, and drawing was performed by changing the drawing place.
Immediately after the drawing, a clean track Mark 5 (manufactured by Tokyo Electron Ltd.) was used, and a post-exposure bake (PEB) was performed on a hot plate at 90 ° C. for 60 seconds, and a paddle was filled with 2.38 mass% TMAH aqueous solution for 30 seconds Development was performed to obtain a positive pattern.

Next, the amount of dimensional variation when left in vacuum using a length measuring SEM (S-7280, manufactured by Hitachi, Ltd.) was determined by the following method. In other words, the difference between 0.12 μm line and space and the 0.12 μm line and space is obtained with an exposure amount that resolves 0.12 μm line and space at 1: 1, and the amount of dimensional variation It was. In the dimension fluctuation amount, plus indicates that the resist sensitivity is increased by being left in vacuum, and minus indicates that the sensitivity is decreased. The results are shown in Table 9.
In electron beam exposure, by applying the resist protective film (TC-20 to 28) of the present invention, the stability in exposure to vacuum after exposure was improved.

  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 (19)

A polymer compound having a repeating unit represented by the following general formula (1) and having a weight average molecular weight in the range of 1,000 to 500,000.

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. X represents any structure represented by the general formulas (X-1) to (X-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. R ⁴ represents a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded. A part of the hydrogen atom may be substituted with a halogen atom, and a part of the methylene group may be substituted with an oxygen atom or a carbonyl group, wherein the general formula (X-1) is R ^2a , Linked to the — (C═O) —O— bond of the repeating unit (1) via any of R ^2b , R ^3a and R ^3b . In general formula (X-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a and R ^7b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a carbon number of 1 to 15. A linear, branched or cyclic monovalent organic group, and two of them may be bonded together to form a ring together with the carbon atom to which they are bonded. Is linked to the — (C═O) —O— bond of the repeating unit (1) via any one of R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b . R ^8a , R ^8b , R ^9a and R ^9b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. It represents a group, bonded two of these together may form a ring together with the carbon atoms to which they are attached. formula (X-3) is R ^{8a, 8b,} R ^9a, repeating units via one of the R ^9b (1) -. Linked to (C = O) -O- bond ^{Incidentally, R 2a, R 2b, R} 3a, R 3b, R 5a, R ^5b , R ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b as a linking group to the — (C═O) —O— bond of the repeating unit (1) In the case of linking, in the above definition, the linking group is a group in which one hydrogen atom contained in the organic group is eliminated and this elimination site is a bond. A polymer compound having a weight average molecular weight in the range of 1,000 to 500,000, which has a repeating unit represented by the following general formula (2).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. Y represents any structure represented by the general formulas (Y-1) to (Y-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Y-1) is R ^2a , R ^2b , R ^3a , R ^3b. In the general formula (Y-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a are linked to the — (C═O) —O— bond of the repeating unit (2). R ^7b each independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. Two of these may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Y-2) is represented by R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b is linked to the — (C═O) —O— bond of the repeating unit (2) through R ^7a , R ^8a , R ^8b , R ^9a and R ^9b are each represented by formula (Y-3) Independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms, two of which are bonded to each other A ring may be formed together with the carbon atom of General Formula (Y-3) is represented by — (C═O) — of repeating unit (2) through any of R ^8a , R ^8b , R ^9a and R ^9b. coupled to O- linked .R ¹⁰ is a straight, branched or cyclic alkyl group of 1 to 19 carbon atoms, partially halogen atom hydrogen atom May be substituted, also part of the methylene groups may be replaced by oxygen atom, or a carbonyl group. In ^{addition, R 2a, R 2b, R} 3a, R 3b, R 5a, R 5b, R ^When connecting to the — (C═O) —O— bond of the repeating unit (2) using any one of ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b as a linking group, (In the above definition, the linking group is a group in which one hydrogen atom contained in the organic group is eliminated and this elimination site is a bond.) A polymer compound having a weight average molecular weight in the range of 1,000 to 500,000, characterized by having a repeating unit represented by the following general formula (3).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. Z represents any structure represented by the general formulas (Z-1) to (Z-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Z-1) is R ^2a , R ^2b , R ^3a , R ^3b. In the general formula (Z-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a are linked to the — (C═O) —O— bond of the repeating unit (3). R ^7b each independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Z-2) is R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b is linked to the — (C═O) —O— bond of the repeating unit (3) through which R ^8a , R ^8b , R ^9a and R ^9b are each represented by the following formula (Z-3): Independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms, two of which are bonded to each other A ring may be formed together with the carbon atom of General Formula (Z-3) is — (C═O) — of repeating unit (3) through any of R ^8a , R ^8b , R ^9a , and R ^9b. coupled to O- linked .R ¹¹ is hydrogen atom or a number from 1 to 18 linear carbon atoms, a branched or cyclic alkyl group, a part of hydrogen atoms May be substituted with androgenic atom, also a part of the methylene groups is an oxygen atom, or may .R ¹² be substituted by a carbonyl group is a straight 1-19 carbon atoms, branched or cyclic an alkyl group, part of the hydrogen atoms may be substituted with a halogen atom, a part of the methylene groups is an oxygen atom or .R ¹¹ and R ¹² may be substituted by a carbonyl group, the bond A cyclic structure may be formed together with the carbon atom and oxygen atom to which they are bonded, and R ^2a , R ^2b , R ^3a , R ^3b , R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , When any of R ^7b , R ^8a , R ^8b , R ^9a and R ^9b is linked to the — (C═O) —O— bond of the repeating unit (3), the linking group is defined as above. One hydrogen atom contained in the organic group is eliminated, and this elimination site is regarded as a bond. A group. ) The polymer compound according to any one of claims 1 to 3, further comprising one or more of repeating units represented by the following general formulas (4a) to (4f).

Wherein R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group. R ^13a and R ^13b are a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, R ^13a and R ^13b can be bonded to each other to form a ring together with the carbon atom to which they are bonded, R ¹⁴ is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, fluorine R ¹⁵ is a linear, branched or cyclic fluorinated alkyl group having 1 to ¹⁵ carbon atoms, and R ¹⁶ is an acid labile group. A resist protective film material comprising a polymer compound having a repeating unit represented by the following general formula (1).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. X represents any structure represented by the general formulas (X-1) to (X-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. R ⁴ represents a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded. A part of the hydrogen atom may be substituted with a halogen atom, and a part of the methylene group may be substituted with an oxygen atom or a carbonyl group, wherein the general formula (X-1) is R ^2a , Linked to the — (C═O) —O— bond of the repeating unit (1) via any of R ^2b , R ^3a and R ^3b . In general formula (X-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a and R ^7b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a carbon number of 1 to 15. A linear, branched or cyclic monovalent organic group, and two of them may be bonded together to form a ring together with the carbon atom to which they are bonded. Is linked to the — (C═O) —O— bond of the repeating unit (1) via any one of R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b . R ^8a , R ^8b , R ^9a and R ^9b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. It represents a group, bonded two of these together may form a ring together with the carbon atoms to which they are attached. formula (X-3) is R ^{8a, 8b,} R ^9a, repeating units via one of the R ^9b (1) -. Linked to (C = O) -O- bond ^{Incidentally, R 2a, R 2b, R} 3a, R 3b, R 5a, R ^5b , R ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b as a linking group to the — (C═O) —O— bond of the repeating unit (1) In the case of linking, in the above definition, the linking group is a group in which one hydrogen atom contained in the organic group is eliminated and this elimination site is a bond. A resist protective film material comprising a polymer compound having a repeating unit represented by the following general formula (2).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. Y represents any structure represented by the general formulas (Y-1) to (Y-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Y-1) is R ^2a , R ^2b , R ^3a , R ^3b. In the general formula (Y-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a are linked to the — (C═O) —O— bond of the repeating unit (2). R ^7b each independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. Two of these may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Y-2) is represented by R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b is linked to the — (C═O) —O— bond of the repeating unit (2) through R ^7a , R ^8a , R ^8b , R ^9a and R ^9b are each represented by formula (Y-3) Independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms, two of which are bonded to each other A ring may be formed together with the carbon atom of General Formula (Y-3) is represented by — (C═O) — of repeating unit (2) through any of R ^8a , R ^8b , R ^9a and R ^9b. coupled to O- linked .R ¹⁰ is a straight, branched or cyclic alkyl group of 1 to 19 carbon atoms, partially halogen atom hydrogen atom May be substituted, also part of the methylene groups may be replaced by oxygen atom, or a carbonyl group. In ^{addition, R 2a, R 2b, R} 3a, R 3b, R 5a, R 5b, R ^When connecting to the — (C═O) —O— bond of the repeating unit (2) using any one of ^6a , R ^6b , R ^7a , R ^7b , R ^8a , R ^8b , R ^9a , R ^9b as a linking group, (In the above definition, the linking group is a group in which one hydrogen atom contained in the organic group is eliminated and this elimination site is a bond.) A resist protective film material comprising a polymer compound having a repeating unit represented by the following general formula (3).

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. Z represents any structure represented by the general formulas (Z-1) to (Z-3). -1), R ^2a , R ^2b , R ^3a and R ^3b are each independently a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Z-1) is R ^2a , R ^2b , R ^3a , R ^3b. In the general formula (Z-2), R ^5a , R ^5b , R ^6a , R ^6b , R ^7a are linked to the — (C═O) —O— bond of the repeating unit (3). R ^7b each independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms. And two of them may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and the general formula (Z-2) is R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , R ^7b is linked to the — (C═O) —O— bond of the repeating unit (3) through which R ^8a , R ^8b , R ^9a and R ^9b are each represented by the following formula (Z-3): Independently represents a single bond, a hydrogen atom, a hydroxyl group, a halogen atom, or a linear, branched or cyclic monovalent organic group having 1 to 15 carbon atoms, two of which are bonded to each other A ring may be formed together with the carbon atom of General Formula (Z-3) is — (C═O) — of repeating unit (3) through any of R ^8a , R ^8b , R ^9a , and R ^9b. coupled to O- linked .R ¹¹ is hydrogen atom or a number from 1 to 18 linear carbon atoms, a branched or cyclic alkyl group, a part of hydrogen atoms May be substituted with androgenic atom, also a part of the methylene groups is an oxygen atom, or may .R ¹² be substituted by a carbonyl group is a straight 1-19 carbon atoms, branched or cyclic an alkyl group, part of the hydrogen atoms may be substituted with a halogen atom, a part of the methylene groups is an oxygen atom or .R ¹¹ and R ¹² may be substituted by a carbonyl group, the bond A cyclic structure may be formed together with the carbon atom and oxygen atom to which they are bonded, and R ^2a , R ^2b , R ^3a , R ^3b , R ^5a , R ^5b , R ^6a , R ^6b , R ^7a , When any of R ^7b , R ^8a , R ^8b , R ^9a and R ^9b is linked to the — (C═O) —O— bond of the repeating unit (3), the linking group is defined as above. One hydrogen atom contained in the organic group is eliminated, and this elimination site is regarded as a bond. A group. ) Furthermore, the high molecular compound which has 1 or 2 or more of the repeating units represented by the following general formula (4a)-(4f) is included, The any one of Claims 5 thru | or 7 characterized by the above-mentioned. Resist protective film material.

Wherein R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group. R ^13a and R ^13b are a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, R ^13a and R ^13b can be bonded to each other to form a ring together with the carbon atom to which they are bonded, R ¹⁴ is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, fluorine R ¹⁵ is a linear, branched or cyclic fluorinated alkyl group having 1 to ¹⁵ carbon atoms, and R ¹⁶ is an acid labile group. The resist protective film material according to any one of claims 5 to 8, comprising a polymer compound having a repeating unit represented by the following general formula (5) or (6).

(Wherein R ^31a and R ^31b are a hydrogen atom or a methyl group. R ³² is a single bond, an alkylene group having 1 to 4 carbon atoms, a phenylene group, —C (═O) —O—, —C (= O) -NH- R ³³ is a single bond or a linear, branched or cyclic alkylene group having 1 to 8 carbon atoms R ^{34a to} R ^34d and R ^{36a to} R ^36c is each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an alkenyl group, an oxoalkyl group or an oxoalkenyl group, an aryl group having 6 to 20 carbon atoms, Any one of 12 aralkyl groups or aryloxoalkyl groups, and some or all of the hydrogen atoms may be substituted with alkoxy groups, and R ^{34a to} R ^34d and R ^{36a to} R ^36c may be Nitrogen atom, ether group, ester group, hydroxy Or two of which may contain a carboxyl group .R ^34a to R ^34d and R ^36a to R ^36c, taken together may form a ring together with the nitrogen atom to which they are attached, in which case each independently an alkylene group of 3 to 15 carbon atoms, or .R ³⁵ showing a heteroaromatic ring having a nitrogen atom in the formula in the ring is linear C1-8, branched or cyclic alkylene group R ³⁷ represents a carbonyl group, an ester group, an ether group, or a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms which may have a halogen atom, or a carbonyl group, an ester group, It represents any of an ether group, a halogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms which may have a fluorinated alkyl group.) The resist protective film material according to any one of claims 5 to 9, wherein the polymer compound according to claim 9 further contains a repeating unit represented by the following general formula (7).

(Wherein, R ^31c is a hydrogen atom or a methyl group .R ^38a and R ^38b is a hydrogen atom, or of the straight, a branched or cyclic alkyl group, R ^38a and R ^38b Can also combine to form a ring with the carbon atoms to which they are attached.)   The resist protective film material according to any one of claims 1 to 10, further comprising a solvent.   The resist protective film material according to claim 11, wherein the solvent is an ether compound having 8 to 12 carbon atoms.   As an ether compound having 8 to 12 carbon atoms, di-n-butyl ether, di-isobutyl ether, di-sec-butyl ether, di-n-pentyl ether, di-isopentyl ether, di-sec-pentyl ether, di-t 13. The resist protective film material according to claim 11 or 12, wherein at least one solvent selected from amyl ether and di-n-hexyl ether is used.   14. The resist protective film material according to claim 12, wherein 0.1 to 90% by mass of a higher alcohol having 4 to 10 carbon atoms is used in addition to the ether compound.   (1) a step of applying a resist material on the substrate; (2) a step of forming a resist protective film on the photoresist film using the resist protective film material according to any one of claims 5 to 14; And (3) a step of inserting a liquid between the projection lens and the wafer after the heat treatment, and exposing with a high energy beam through a photomask, and (4) a step of developing with a developer. A pattern forming method.   The pattern forming method according to claim 15, wherein the liquid inserted between the projection lens and the substrate in the exposure step is water.   17. The pattern forming method according to claim 15, wherein a high energy ray having a wavelength in the range of 180 to 250 nm is used as the exposure light source.   18. The development step according to claim 15, wherein 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. The pattern forming method according to claim 1.   Use of the protective film material according to any one of claims 5 to 14 in lithography in which a protective film is formed on a photoresist layer formed on a mask blank, followed by electron beam exposure in a vacuum and then developing. A characteristic pattern forming method.