JP3925473B2 - Polysiloxane and radiation-sensitive resin composition - Google Patents

Description

  The present invention relates to a novel polysiloxane having a fluorine atom-containing norbornane skeleton, and a radiation-sensitive resin composition containing the polysiloxane and useful for microfabrication.

  In recent years, demands for higher density and higher integration of LSIs (highly integrated circuits) are increasing, and along with this, miniaturization of wiring patterns is also progressing rapidly.

As one of the means that can cope with such miniaturization of the wiring pattern, there is a method of shortening the radiation used in the lithography process. In recent years, g-line (wavelength 436 nm), i-line (wavelength 365 nm), etc. Instead of ultraviolet rays, far ultraviolet rays represented by KrF excimer laser (wavelength 248 nm) or ArF excimer laser (wavelength 193 nm), electron beam, X-ray, etc. are used, and F ₂ excimer laser (wavelength) The use of 157 nm) is also under consideration.

  By the way, in the conventional resist composition, a novolak resin, poly (vinylphenol) or the like has been used as a resin component. However, these materials contain an aromatic ring in the structure and have strong absorption at a wavelength of 193 nm. Therefore, for example, in a lithography process using an ArF excimer laser, high accuracy corresponding to high sensitivity, high resolution, and high aspect ratio cannot be obtained.

  Therefore, there is a demand for a resin component for resist that is transparent to a wavelength of 200 nm or less and has a dry etching resistance equivalent to or higher than that of an aromatic ring. One of them is a siloxane polymer, and MIT RRKunz et al. Have shown that a polysiloxane polymer has excellent transparency at a wavelength of 200 nm or less, particularly 157 nm, and this polymer is 193 nm or less. It is reported that it is suitable for a resist material in a lithography process using a wavelength of (see, for example, Non-Patent Document 1). It is also known that polysiloxane polymers are excellent in dry etching resistance, and among them, a resist containing polyorganosilsesquioxane having a ladder structure has high plasma resistance.

  On the other hand, some resist materials using siloxane polymers have already been reported. Namely, a radiation sensitive resin using polysiloxane having acid dissociable groups in the side chain in which acid dissociable groups such as carboxylic acid ester groups and phenol ether groups are bonded to silicon atoms via one or more carbon atoms. Composition (for example, see Patent Document 1), positive resist using a polymer in which the carboxyl group of poly (2-carboxyethylsiloxane) is protected with an acid-dissociable group such as t-butyl group (for example, Patent Document 2) And a resist resin composition using a polyorganosilsesquioxane having an acid dissociable ester group (for example, see Patent Document 3). However, resist materials using these conventional acid-dissociable group-containing siloxane polymers are still not at a satisfactory level in terms of basic physical properties as resists such as transparency to radiation, resolution, and developability. .

  Furthermore, it has a non-aromatic monocyclic or polycyclic hydrocarbon group having a carboxyl group or a bridged cyclic hydrocarbon group in the side chain, and at least a part of the carboxyl group is an acid labile group. A substituted siloxane-based polymer and a resist material using the polymer have been reported (for example, see Patent Document 4). The resist material has a small absorption of a KrF excimer laser or an ArF excimer laser, and has a pattern shape. It is said to be excellent and also excellent in sensitivity, resolution, dry etching resistance and the like.

However, this resist material also has a problem in the absorption of the F ₂ excimer laser, and many defects remain in the function as a resist material applied to short-wavelength radiation.

On the other hand, although a resist material that solves these problems has been reported (see, for example, Patent Document 5), even if the siloxane-based polymer of Patent Document 5 is included, a siloxane-based polymer useful as a resin component of the resist material is included. Development of new siloxane-based polymers that can provide resist materials with excellent basic physical properties as resists, such as resolution and coating properties, while having few types, effectively responding to short-wavelength radiation, and having high dry etching resistance This is an important issue from the viewpoint of technological development that can cope with the rapid miniaturization of LSIs.
J. Photopolym. Sci. Technol., Vol.12, No.4, P.561-570 (1999) Japanese Patent Laid-Open No. 5-323611 JP-A-8-160623 Japanese Patent Laid-Open No. 11-60733 JP-A-11-302382 JP 2003-20335 A

The object of the present invention is to effectively respond to radiation having a wavelength of 200 nm or less typified by an ArF excimer laser or F ₂ excimer laser, to have high transparency to radiation, and to have excellent resolution, coating properties, etc. It is an object of the present invention to provide a novel polysiloxane having a fluorine atom-containing norbornane skeleton, and a radiation-sensitive resin composition containing the polysiloxane.

The present invention, first,
A structural unit represented by the following formula (I) (hereinafter referred to as “structural unit (I)”) and a structural unit represented by the following formula (II) (hereinafter referred to as “structural unit (II)”). At least one selected from the group, a structural unit represented by the following formula (III) (hereinafter referred to as “structural unit (III)”), and a structural unit represented by the following formula (IV) (hereinafter referred to as “structure”). A polysiloxane having a polystyrene-reduced weight average molecular weight of 500 to 1,000,000 by gel permeation chromatography (GPC) (hereinafter referred to as “polysiloxane”) having at least one selected from the group of units (IV) ”) (A) ")).

〔式（Ｉ）および式（II）において、各ｎは相互に独立に０または１であり、式（II）において、Ｘ¹ は水素原子、炭素数１〜２０の１価の炭化水素基、炭素数１〜２０の１価のハロゲン化炭化水素基、ハロゲン原子または１級、２級もしくは３級のアミノ基を示す。〕

[In Formula (I) and Formula (II), each n is independently 0 or 1, and in Formula (II), X ¹ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, A monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, or a primary, secondary or tertiary amino group is shown. ]

〔式（III)および式（IV）において、各Ｂは相互に独立に水素原子またはフッ素原子を示し、各ｐは相互に独立に１〜１０の整数であり、各ｍは相互に独立に０または１であり、式（IV）において、Ｘ² は水素原子、炭素数１〜２０の１価の炭化水素基、炭素数１〜２０の１価のハロゲン化炭化水素基、ハロゲン原子または１級、２級もしくは３級のアミノ基を示す。〕
本発明は、第二に、
（イ）ポリシロキサン（Ａ）のうち、酸解離性基を有するアルカリ不溶性またはアルカリ難溶性の樹脂であって、該酸解離性基が解離したときアルカリ易溶性となる樹脂（以下、「ポリシロキサン（Ａ１）」という。）、並びに（ロ）感放射線性酸発生剤（以下、単に「酸発生剤」という。）を含有することを特徴とする感放射線性樹脂組成物、からなる。

[In Formula (III) and Formula (IV), each B independently represents a hydrogen atom or a fluorine atom, each p is independently an integer of 1 to 10, and each m is independently 0. Or in formula (IV), X ² is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a halogen atom or a primary atom. A secondary or tertiary amino group is shown. ]
The present invention secondly,
(A) Among the polysiloxanes (A), an alkali-insoluble or hardly alkali-soluble resin having an acid-dissociable group, which is readily alkali-soluble when the acid-dissociable group is dissociated (hereinafter referred to as “polysiloxane”) (A1) "), and (b) a radiation-sensitive resin composition characterized by containing a radiation-sensitive acid generator (hereinafter simply referred to as" acid generator ").

Hereinafter, the present invention will be described in detail.
Polysiloxane (A)
In formula (II) and formula (IV), examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms of X ¹ and X ² include, for example, methyl group, ethyl group, cyclopentyl group, cyclohexyl group, norbornyl group, tetra A cyclodecanyl group and the like, and examples of the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms of X ¹ and X ² include a trifluoromethyl group, 2,2,2-trifluoroethyl, and the like. Group, pentafluoroethyl group and the like, and examples of the halogen atom of X ¹ and X ² include a fluorine atom and a chlorine atom, and the primary, secondary or secondary of X ¹ and X ² Examples of the tertiary amino group include an amino group, a dimethylamino group, a diethylamino group, a dicyclopentylamino group, a dicyclohexylamino group, and a diphenylamino group. Can.

  The polysiloxane (A) can optionally have one or more structural units other than the structural units (I) to (IV) (hereinafter referred to as “other structural units”).

  Preferred other structural units include, for example, a structural unit represented by the following formula (V) (hereinafter referred to as “structural unit (V)”) and a structural unit represented by the following formula (VI) (hereinafter referred to as “ Structural unit (VI) ”), structural unit represented by the following formula (VII) (hereinafter referred to as“ structural unit (VII) ”), structural unit represented by the following formula (VIII) (hereinafter referred to as“ structural unit (VI) ”). Structural unit (VIII) ") and the like.

〔式（Ｖ）および式（VI）において、各Ｄは相互に独立に水素原子、フッ素原子、トリフルオロメチル基または１価の酸素含有有機基を示し、各ｑは相互に独立に０または１であり、式（VI）において、Ｘ³ は水素原子、炭素数１〜２０の１価の炭化水素基、炭素数１〜２０の１価のハロゲン化炭化水素基、ハロゲン原子または１級、２級もしくは３級のアミノ基を示す。〕

[In the formulas (V) and (VI), each D independently represents a hydrogen atom, a fluorine atom, a trifluoromethyl group or a monovalent oxygen-containing organic group, and each q independently represents 0 or 1 In the formula (VI), X ³ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a halogen atom or primary, Indicates a tertiary or tertiary amino group. ]

〔式（VII)および式（VIII) において、各Ｘ⁴ は相互に独立に水素原子、水酸基、炭素数１〜２０の１価の炭化水素基、炭素数１〜２０の１価のハロゲン化炭化水素基、ハロゲン原子または１級、２級もしくは３級のアミノ基を示し、式（VIII) において、Ｘ⁵ は水素原子、炭素数１〜２０の１価の炭化水素基、炭素数１〜２０の１価のハロゲン化炭化水素基、ハロゲン原子または１級、２級もしくは３級のアミノ基を示す。〕
式（Ｖ）および式（VI）において、Ｄの１価の酸素含有有機基としては、例えば、ｔ−ブトキシカルボニル基、テトラヒドロピラニルオキシカルボニル基、１−エトキシエトキシカルボニル基、ｔ−ブチルジメチルシリルオキシカルボニル基等の酸解離性基；メトキシ基、エトキシ基、ｎ−プロポキシ基、ｎ−ブトキシ基、ｔ−ブトキシ基等のアルコキシル基；トリフルオロメトキシ基、ペンタフルオロエトキシ基、ヘプタフルオロ−ｎ−プロポキシ基、ノナフルオロ−ｎ−ブトキシ基等のフルオロアルコキシル基等を挙げることができる。

[In the formulas (VII) and (VIII), each X ⁴ independently represents a hydrogen atom, a hydroxyl group, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent halogenated carbon atom having 1 to 20 carbon atoms. A hydrogen group, a halogen atom or a primary, secondary or tertiary amino group, wherein in formula (VIII), X ⁵ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or 1 to 20 carbon atoms; A monovalent halogenated hydrocarbon group, a halogen atom, or a primary, secondary or tertiary amino group. ]
In the formula (V) and the formula (VI), examples of the monovalent oxygen-containing organic group represented by D include, for example, a t-butoxycarbonyl group, a tetrahydropyranyloxycarbonyl group, a 1-ethoxyethoxycarbonyl group, and a t-butyldimethylsilyl group. Acid-dissociable groups such as oxycarbonyl group; alkoxyl groups such as methoxy group, ethoxy group, n-propoxy group, n-butoxy group, t-butoxy group; trifluoromethoxy group, pentafluoroethoxy group, heptafluoro-n- Examples thereof include fluoroalkoxy groups such as propoxy group and nonafluoro-n-butoxy group.

In addition, as the monovalent hydrocarbon group having 1 to 20 carbon atoms, the monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, the halogen atom, or the primary, secondary, or tertiary amino group of X ³ , Examples thereof include the same groups as the corresponding groups exemplified for X ¹ in formula (II) and X ² in formula (IV).

In the formulas (VII) and (VIII), X ⁴ and X ⁵ monovalent hydrocarbon group having 1 to 20 carbon atoms, monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, halogen atom or primary Examples of the secondary or tertiary amino group include the same groups as the corresponding groups exemplified for X ¹ in the formula (II) and X ² in the formula (IV).

  The specific content of each structural unit in the polysiloxane (A) varies depending on the type and combination thereof, the use of the polysiloxane (A), etc., and the preferred content of each structural unit in each case is: A person skilled in the art can select appropriately by a test or the like.

  For example, in the case of polysiloxane (A1) used in a radiation-sensitive resin composition useful as a resist for fine processing using radiation such as deep ultraviolet rays, electron beams, and X-rays, the structural unit (I) and the structural unit ( The total content of II) is usually from 5 to 90 mol%, preferably from 30 to 80 mol%, based on the total structural units, and the total content of the structural units (III) and (IV). Is usually 1 to 50 mol%, preferably 2 to 40 mol%, based on the total structural units, and the content of other structural units having an acid-dissociable group is usually based on the total structural units. , 10 to 60 mol%, preferably 15 to 40 mol%, and the content of other structural units is usually 90 mol% or less, preferably 80 mol% or less, based on the total structural units. is there.

  The weight average molecular weight (hereinafter referred to as “Mw”) in terms of polystyrene measured by gel permeation chromatography (GPC) of the polysiloxane (A) is 500 to 1,000,000, preferably 500 to 50,000.

  The polysiloxane (A) includes, for example, at least one silane compound selected from the group of triethoxysilane corresponding to the structural unit (I) and diethoxysilane corresponding to the structural unit (II), and the structural unit (III). And at least one silane compound selected from the group of diethoxysilane corresponding to structural unit (IV), optionally in the presence of a silane compound corresponding to another structural unit, It can be produced by polycondensation in a solvent in the presence of an acidic catalyst or a basic catalyst. In this polycondensation, it is preferable that the polycondensation is carried out in the presence of an acidic catalyst, and then a basic catalyst is added for further reaction. In addition, each silane compound can also be used partially or entirely as a partial condensate.

  Polysiloxane (A) is particularly useful as a resin component in a resist for microfabrication using radiation such as deep ultraviolet rays, electron beams, and X-rays, and is used alone or in combination with general polysiloxanes, for example, It is also useful as a molded product, film, laminate material, paint component, and the like.

In addition, polysiloxane (A1) has a property of being highly transparent to radiation, and can be used very particularly suitably as a resin component in a radiation-sensitive resin composition useful as a resist.
Radiation sensitive resin composition- polysiloxane (A1)-
In the radiation sensitive resin composition of the present invention, the polysiloxane (A1) can be used alone or in admixture of two or more, and together with the polysiloxane (A1), one or more other polysiloxanes can be used. Can be used together.

As said other polysiloxane, what has at least 1 sort (s) of the said structural units (V)-(VIII) can be mentioned, for example.
-Acid generator-
Examples of the acid generator include sulfonium salts such as triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 10-camphorsulfonate, Onium salt compounds such as thiophenium salts and iodonium salts; sulfone compounds such as β-ketosulfone, β-sulfonylsulfone and α-diazo compounds of these compounds; sulfonic acid compounds such as sulfonate esters and sulfonate imides; carboxylate esters Carboxylic acid compounds such as carboxylic acid imides; diazoketone compounds such as 1,3-diketo-2-diazo compounds and diazobenzoquinone compounds; haloalkyl group-containing hydrocarbon compounds, halo Etc. and a halogen-containing compound such as alkyl group-containing heterocyclic compounds.

  These acid generators can be used alone or in admixture of two or more.

The usage-amount of an acid generator is 0.1-10 weight part normally with respect to 100 weight part of all the polysiloxane components, Preferably it is 0.5-7 weight part.
-Additives-
Examples of the radiation sensitive resin composition of the present invention include imidazoles such as imidazole, 4-methylimidazole, 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, In addition to nitrogen-containing heterocyclic compounds such as pyridines, it is preferable to add one or more acid diffusion control agents such as (cyclo) alkylamines, aromatic amines, amide group-containing compounds and urea compounds.

  The compounding amount of the acid diffusion controller is preferably 100 mol% or less, particularly preferably 50 mol% or less with respect to the acid generator.

Further, as additives other than the acid diffusion control agent, a dissolution control agent, a surfactant, an antihalation agent, an adhesion assistant, a storage stabilizer, an antifoaming agent, and the like can be blended.
-Preparation of composition solution-
The radiation-sensitive resin composition of the present invention is usually dissolved in a solvent so that the total solid content is usually 1 to 25% by weight, preferably 2 to 15% by weight. A composition solution is prepared by filtering with a filter having a pore size of about 0.2 μm.
-Method for forming resist pattern-
In the radiation-sensitive resin composition of the present invention, an acid is generated from the acid generator by exposure, and the acid-dissociable group in the polysiloxane component is dissociated by the action of the acid. The solubility in the solution is increased, and the exposed portion is dissolved and removed with an alkali developer, whereby a positive resist pattern is obtained.

When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution is coated with, for example, a silicon wafer or aluminum by an appropriate application means such as spin coating, cast coating, or roll coating. A resist film is formed by coating on a wafer or a substrate on which a lower layer film has been formed in advance, and a predetermined resist pattern is formed after heat treatment (hereinafter referred to as “PB”) in some cases. The resist film is exposed to form. The radiation used at that time is preferably radiation having a wavelength of 200 nm or less, and particularly, ArF excimer laser (wavelength 193 nm) or F ₂ excimer laser (wavelength 157 nm) is preferred.

  In the present invention, it is preferable to perform heat treatment (hereinafter referred to as “PEB”) after exposure. The heating condition of PEB varies depending on the composition of the radiation sensitive resin composition, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

  In the present invention, an organic or inorganic lower layer film can be formed on the substrate to be used, and a protective film can be provided on the resist film.

  Next, the exposed resist film is developed to form a predetermined resist pattern.

  Examples of the developer used for development include sodium hydroxide, potassium hydroxide, aqueous ammonia, ethylamine, diethylamine, triethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo. An alkaline aqueous solution in which at least one of alkaline compounds such as [5.4.0] -7-undecene and 1,5-diazabicyclo- [4.3.0] -5-nonene is dissolved is preferable.

  Further, an organic solvent or a surfactant can be added to the developer composed of the alkaline aqueous solution.

  In addition, after developing with the developing solution which consists of alkaline aqueous solution, generally it wash | cleans with water and dries.

  The polysiloxane (A) of the present invention is particularly useful as a resin component in a fine processing resist using radiation such as deep ultraviolet rays, electron beams, and X-rays.

Further, the radiation-sensitive resin composition of the present invention using polysiloxane (A1) as the resin component has a wavelength of 200 nm or less such as far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm) or F ₂ excimer laser (wavelength 157 nm). As a radiation-sensitive resin composition that effectively responds to radiation, is highly transparent to radiation, and is useful as a resist with excellent resolution, coating properties, etc. It can be used very suitably for representative microfabrication.

  Hereinafter, the embodiment of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Here, the part is based on weight.

Each measurement and evaluation in Examples and Comparative Examples was performed as follows.
Mw:
Using a GPC column (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation, monodisperse polystyrene as the standard under the analysis conditions of flow rate 1.0 ml / min, elution solvent tetrahydrofuran, column temperature 40 ° C. Measured by gel permeation chromatography (GPC).
Absorption coefficient:
Evaluation was made by either of the following two methods.
Method 1—The composition solution was applied on a magnesium fluoride substrate by spin coating, and then PB was performed on a hot plate at 140 ° C. for 90 seconds to form a resist film having a thickness of 1,000 mm. Then, the transmittance at a wavelength of 157 nm was measured for this coating, and the extinction coefficient was calculated.
Method 2—After the composition solution was applied onto a silicon substrate by spin coating, PB was performed on a hot plate at 140 ° C. for 90 seconds to form a resist film having a thickness of about 1,000 mm. Thereafter, the optical constants (n and k) of the film were obtained by a spectroscopic ellipsometer, and the extinction coefficient at a wavelength of 157 nm was calculated.
Synthesis example 1
To a three-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, 24 g of triethoxysilane and 3,3-difluoro-2- (trifluoromethyl) bicyclo [2.2.1] hept-5-ene- After charging 20.5 g of 2-ol and stirring at room temperature, 0.2 ml of 0.2 mol i-propanol solution of chloroplatinic acid (H ₂ PtCl ₆ ) was added to start the reaction, and at 80 ° C. Heated for 18 hours. Thereafter, the reaction solution was returned to room temperature, diluted with n-hexane, and then filtered through a suction funnel with celite, and the obtained filtrate was distilled off under reduced pressure to obtain a crude product. Thereafter, the crude product was purified by distillation to obtain 19.2 g of a compound as a fraction having a boiling point of 95 to 98 ° C. at 0.75 mmHg.

This compound was subjected to NMR analysis (chemical shift δ) and gas chromatography-mass spectrometry (GC-MS) using ¹ H, ¹³ C, ¹⁹ F and ²⁹ Si, and was as follows. ) (Hereinafter referred to as “silane compound (a-1)”).

¹Ｈ−ＮＭＲスペクトル（δ；単位ｐｐｍ）：
１．４〜２．５（ノルボルネン環）；
１．６（ＣＨ₃ 部）；
２．８〜３．４（橋頭部）；
４．２（ＣＨ₂ 部）。
¹³Ｃ−ＮＭＲスペクトル（δ；単位ｐｐｍ）：
１４〜１５．５（ケイ素原子と結合している炭素原子）；
１８（ＣＨ₃ 部）；
２２〜２４、３１〜３４（以上、ノルボルネン環のＣＨ₂ 部）；
４２〜４７（橋頭部）；
５９（Ｏ−ＣＨ₂ 部）；
７８〜８２（ＣＦ₃ 部）；
１２２〜１２９（ＣＦ₂ 部およびＣ（ＣＦ₃)ＯＨ部）。
¹⁹Ｆ−ＮＭＲスペクトル（δ；単位ｐｐｍ）：
−１２３〜−１２１、−１２０〜−１１６、−１１１〜−１０８（以上、
ＣＦ₂ 部）；
−７７〜−７２（ＣＦ₃ 部）。
²⁹Ｓｉ−ＮＭＲスペクトル（δ；単位ｐｐｍ）：
−４８〜−５１。
ＧＣ−ＭＳ（ｍ／ｅ）ＣＩ［Ｍ＋Ｈ⁺ ］：
３７９。
実施例１〜３および比較例１〜２
撹拌機、還流冷却器、温度計を装着した３つ口フラスコに、表１に示すシラン化合物および表１に示す量の１．７５重量％蓚酸水溶液と、４−メチル−２−ペンタノン（ＭＩＢＫ）３０ｇを仕込み、撹拌しながら、８０℃で６時間反応させた。その後反応容器を氷冷して、反応を停止させたのち、反応溶液を分液ロートに移して、水層を廃棄し、さらにイオン交換水を加えて水洗して、反応溶液が中性になるまで水洗を繰り返した。その後、有機層を減圧留去して、表１に示す収量のポリマーを得た。

¹ H-NMR spectrum (δ; unit ppm):
1.4 to 2.5 (norbornene ring);
1.6 (CH ₃ parts);
2.8 to 3.4 (bridge head);
4.2 (CH ₂ part).
¹³ C-NMR spectrum (δ; unit ppm):
14 to 15.5 (carbon atoms bonded to silicon atoms);
18 (CH ₃ parts);
22-24, 31-34 (above, CH ₂ part of norbornene ring);
42-47 (bridge head);
59 (O-CH ₂ parts);
78-82 (CF ₃ parts);
122-129 (CF ₂ parts and C (CF ₃ ) OH parts).
¹⁹ F-NMR spectrum (δ; unit ppm):
-123 to -121, -120 to -116, -1111 to -108 (above,
CF ₂ parts);
-77~-72 (CF ₃ parts).
²⁹ Si-NMR spectrum (δ; unit ppm):
-48 to -51.
GC-MS (m / e) CI [M + H ⁺ ]:
379.
Examples 1-3 and Comparative Examples 1-2
In a three-necked flask equipped with a stirrer, a reflux condenser, and a thermometer, a silane compound shown in Table 1 and a 1.75 wt% aqueous oxalic acid solution in the amount shown in Table 1, and 4-methyl-2-pentanone (MIBK) 30 g was charged and reacted at 80 ° C. for 6 hours with stirring. After cooling the reaction vessel with ice and stopping the reaction, the reaction solution is transferred to a separatory funnel, the aqueous layer is discarded, and ion-exchanged water is added and washed to make the reaction solution neutral. Repeated washing with water. Thereafter, the organic layer was distilled off under reduced pressure to obtain a polymer having a yield shown in Table 1.

  Next, each polymer obtained was dissolved in MIBK in the amount shown in Table 2, distilled water and triethylamine (TEA) in the amounts shown in Table 2 were added, and the mixture was stirred at 80 ° C. for 6 hours in a nitrogen stream. After cooling, an aqueous solution in which 8.0 g of oxalic acid was dissolved in 300 g of distilled water was added and further stirred. Thereafter, the reaction solution was transferred to a separating funnel, the aqueous layer was discarded, and ion-exchanged water was further added and washed, and washing was repeated until the reaction solution became neutral. Thereafter, the organic layer was distilled off under reduced pressure to obtain polysiloxane having a yield and Mw shown in Table 2.

  The structures of the silane compounds (a-2) to (a-5) used in Examples 1 to 3 and Comparative Examples 1 and 2 are as shown in the following formulas (a-2) to (a-5), respectively.

実施例４〜６および比較例３〜４
実施例１〜３および比較例１〜２で得た各ポリシロキサン１００部に対して、表３に示す酸発生剤および酸拡散抑制剤を加えた混合物に、表３に示す溶剤を加えて溶解したのち、孔径０．４５μｍのメンブランフィルターでろ過して、組成物溶液を調製した。

Examples 4-6 and Comparative Examples 3-4
To 100 parts of each of the polysiloxanes obtained in Examples 1 to 3 and Comparative Examples 1 and 2, the solvent shown in Table 3 was added to the mixture of the acid generator and acid diffusion inhibitor shown in Table 3 and dissolved. Then, it filtered with the membrane filter with the hole diameter of 0.45 micrometer, and prepared the composition solution.

  Next, each composition solution was applied onto a silicon substrate by spin coating, and PB was performed on a hot plate at 140 ° C. for 90 seconds to form a resist film.

  At this time, when the coating was uniform, the coating property was “good”, and when striation was observed, the coating property was “bad”, and the coating property was evaluated. Moreover, about the composition solution with favorable applicability | paintability, the light absorption coefficient was evaluated by the above-mentioned method. The evaluation results are shown in Table 3.

  Furthermore, each composition solution was applied by spin coating on the substrate on which the lower layer film (β-1) obtained in the following production example was formed, and PB was performed for 90 seconds on a hot plate maintained at 140 ° C. Thus, a resist film having a thickness of 1,200 mm was formed. Thereafter, each resist film was exposed with an ArF excimer laser (numerical aperture of 0.55) through a reticle while changing the exposure amount, and then subjected to PEB on a hot plate at 110 ° C. for 90 seconds. Then, it developed with the 2.38 weight% tetramethylammonium hydroxide aqueous solution, the line and space pattern (1L1S) was formed, and ArF resolution was evaluated. The evaluation results are shown in Table 3.

Also, the composition solution of Example 4, except that the exposure with an F ₂ excimer laser (numerical aperture 0.85) in the same manner as in the case of ArF resolution was evaluated F ₂ resolution. As a result, it was confirmed that a 70 nm line and space pattern (1L1S) can be resolved.
Production Example A separable flask equipped with a thermometer was charged with 100 parts of acenaphthylene, 78 parts of toluene, 52 parts of dioxane and 3 parts of azobisisobutyronitrile in a nitrogen atmosphere and stirred at 70 ° C. for 5 hours. Thereafter, 5.2 parts of p-toluenesulfonic acid monohydrate and 40 parts of paraformaldehyde were added, the temperature was raised to 120 ° C., and the mixture was further stirred for 6 hours. Thereafter, the reaction solution was poured into a large amount of i-propanol, and the precipitated polymer was filtered off and dried under reduced pressure at 40 ° C. to obtain a polymer.

This polymer had Mw of 22,000 and was confirmed to have a structural unit represented by the following formula as a result of ¹ H-NMR analysis.

次いで、得られたポリマー１０部、ビス（４−ｔ−ブチルフェニル）ヨードニウム１０−カンファ−スルホネート０．５部、４，４’−〔１−｛４−（１−[ ４−ヒドロキシフェニル ]−１−メチルエチル）フェニル｝エチリデン〕ビスフェノール０．５部およびシクロヘキサノン８９部を均一に混合したのち、孔径０．１μｍのメンブランフィルターでろ過して、下層膜形成用組成物を調製した。 その後、この下層膜形成用組成物を、シリコンウエハー上に、膜厚３００ｎｍの下層膜が得られるように、スピンコートにより塗布したのち、ホットプレート上にて、１８０℃で６０秒間、次いで３００℃で１２０秒間ベークして、下層膜（β−１）を形成した。

Subsequently, 10 parts of the obtained polymer, 0.5 part of bis (4-t-butylphenyl) iodonium 10-camphor-sulfonate, 4,4 ′-[1- {4- (1- [4-hydroxyphenyl]- 1-methylethyl) phenyl} ethylidene] bisphenol and 0.5 part of cyclohexanone were uniformly mixed and then filtered through a membrane filter having a pore size of 0.1 μm to prepare a composition for forming an underlayer film. Thereafter, this composition for forming a lower layer film was applied on a silicon wafer by spin coating so as to obtain a lower layer film having a thickness of 300 nm, and then on a hot plate at 180 ° C. for 60 seconds, and then at 300 ° C. Was baked for 120 seconds to form a lower layer film (β-1).

The acid generator, acid diffusion controller and solvent in Table 3 are as follows. Further, the extinction coefficient values in Table 3 are based on Method 2 in Example 4 and Method 1 in Examples 5 and 6.
Acid generator B-1: Triphenylsulfonium nonafluoro-n-butanesulfonate B-2: Triphenylsulfonium 10-camphorsulfonate
Acid diffusion inhibitor D: 2-phenylbenzimidazole
Solvent MAK: 2-heptanone FAL: 2,2,3,3,4,4,5,5-octafluoro-1-pentanol

Claims (2)

At least one selected from the group of structural units represented by the following formula (I) and structural units represented by the following formula (II), structural units represented by the following formula (III) and the following formula (IV): A polysiloxane having a polystyrene-reduced weight average molecular weight of 500 to 1,000,000 by gel permeation chromatography (GPC), having at least one selected from the group of structural units represented by:

[In Formula (I) and Formula (II), each n is independently 0 or 1, and in Formula (II), X ¹ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, A monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, or a primary, secondary or tertiary amino group is shown. ]

[In Formula (III) and Formula (IV), each B independently represents a hydrogen atom or a fluorine atom, each p is independently an integer of 1 to 10, and each m is independently 0. Or X ² is a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, or a primary, secondary, or tertiary class. The amino group of is shown. ]   (A) Among the polysiloxanes according to claim 1, an alkali-insoluble or hardly-alkali-soluble resin having an acid-dissociable group, which is readily alkali-soluble when the acid-dissociable group is dissociated, and ( B) A radiation-sensitive resin composition containing a radiation-sensitive acid generator.