JP2017120370A - Resist composition and patterning process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist material that offers a high dissolution contrast and minimal LWR and causes no dimensional change on PPD in both positive resist material and negative resist material, and a patterning process using the same.SOLUTION: A resist composition comprises a base polymer and a phosphazene salt compound represented by a specific formula.SELECTED DRAWING: None

Description

  The present invention relates to a resist material containing a phosphazene salt compound and a pattern forming method using the resist material.

  With the high integration and high speed of LSI, pattern rule miniaturization is progressing rapidly. In particular, the expansion of the flash memory market and the increase in storage capacity are leading to miniaturization. As state-of-the-art miniaturization technology, mass production of 65 nm node devices by ArF lithography has been performed, and preparation for mass production of 45 nm nodes by next generation ArF immersion lithography is in progress. The next generation 32nm node includes immersion lithography with ultra-high NA lens combining liquid with higher refractive index than water, high refractive index lens and high refractive index resist material, extreme ultraviolet (EUV) lithography with wavelength of 13.5nm. ArF lithography double exposure (double patterning lithography) and the like are candidates and are being studied.

  For chemically amplified positive resist materials that add an acid generator and generate a deprotection reaction by generating acid by irradiation with light or electron beam (EB), and for chemically amplified negative resist materials that cause a crosslinking reaction with acid, The effect of adding a quencher for the purpose of controlling the diffusion of the light to the unexposed part and improving the contrast was very effective. Therefore, many amine quenchers have been proposed (Patent Documents 1 to 3).

  As miniaturization proceeds and approaches the diffraction limit of light, the contrast of light decreases. Due to the decrease in light contrast, the resolution of the hole pattern and the trench pattern and the focus margin decrease in the positive resist film.

  Attempts have been made to improve the dissolution contrast of the resist film in order to prevent the influence of a decrease in resolution of the resist pattern due to a decrease in light contrast. At the same time, attempts have been made to suppress acid diffusion that causes image blur in the resist pattern.

  A chemically amplified resist material utilizing an acid growth mechanism in which an acid is generated by an acid has been proposed. Normally, the acid concentration increases linearly as the exposure dose increases, but in the case of acid multiplication, the acid concentration rapidly increases nonlinearly with the increase in exposure dose. The acid breeding system has the advantage of further enhancing the advantages of the chemically amplified resist film, such as high contrast and high sensitivity, but the chemically amplified resist has reduced environmental resistance due to amine contamination and reduced limit resolution due to increased acid diffusion distance. In order to further deteriorate the defects of the film, it is a mechanism that is very difficult to control when it is put to practical use.

  Another method for increasing the contrast is to decrease the amine concentration as the exposure dose increases. For this, it is possible to apply a compound that loses its function as a quencher by light.

  The acid labile group used in the (meth) acrylate polymer for ArF has a deprotection reaction that proceeds by using a photoacid generator that generates a sulfonic acid in which the α-position is substituted with fluorine. Deprotection reaction does not proceed with an acid generator that generates a sulfonic acid or carboxylic acid that is not substituted with fluorine. Mixing a sulfonium salt or iodonium salt that generates sulfonic acid that is substituted with fluorine at the α-position with a sulfonium salt or iodonium salt that generates sulfonic acid that is not substituted with fluorine at the α-position will replace the α-position with fluorine. Sulphonium salts and iodonium salts in which sulfonic acid is not generated undergo ion exchange with sulfonic acids in which the α-position is substituted with fluorine. The sulfonic acid in which the α position generated by light is substituted with fluorine is returned to the sulfonium salt or iodonium salt by ion exchange, so that the sulfonic acid or carboxylic acid sulfonium salt or iodonium salt in which the α position is not substituted with fluorine is used. Functions as a quencher.

  Furthermore, the sulfonium salt or iodonium salt in which a sulfonic acid in which the α-position is not substituted with fluorine is generated loses its ability as a quencher by photolysis, and thus functions as a photodegradable quencher. Although the structural formula has not been clarified, it has been shown that the margin of the trench pattern is expanded by the addition of a photodegradable quencher (Non-patent Document 3). However, the effect on performance improvement is slight, and it is desired to develop a quencher that further improves contrast.

  Patent Document 4 proposes an onium salt-type quencher in which basicity is lowered by the generation of a carboxylic acid having an amino group by light and the generation of a lactam by the acid. Due to the mechanism that the basicity is lowered by the acid, the unexposed part where the amount of acid generated is low, the diffusion of the acid is controlled by the high basicity, the overexposed part where the amount of acid generated is high, the basicity of the quencher is reduced This increases the acid diffusion. Thereby, the difference in the acid amount between the exposed part and the unexposed part can be widened, and the contrast is improved. However, this method also has the disadvantage that acid diffusion increases.

  Biguanides and phosphazenes are known as super strong base compounds. These have higher basicity than diazabicycloundecene (DBU), and use of this as a curing reaction catalyst for epoxy has been studied. For example, Patent Documents 5 and 6 propose base generators that generate guanidine, biguanide, phosphazene, 2,5,8,9-tetraaza-1-phosphabicyclo [3.3.3] undecanes by light. Has been. Normally, the amount of acid generated from the photoacid generator increases as the exposure amount increases, but when the photoacid generator and these photobase generators are used in combination, the amount of photoacid generator and the base generator The amount of acid does not increase even if the exposure amount increases. When the amount of photoacid generator is large and the generation efficiency is high, the amount of acid increases as the exposure amount increases, but the amount of increase is small and the contrast of the resist is low.

  A negative tone forming method by organic solvent development has attracted attention. This is because when a hole pattern is to be formed by light exposure, a hole pattern having the smallest pitch can be formed by a combination of a bright pattern mask and a negative resist. Here, there is a problem that the dimension of the pattern after development changes depending on the post exposure bake (PEB) after exposure and the standing time (PPD: Post PEB Delay) between development. It is considered that the cause is that the acid gradually diffuses into the unexposed part during standing at room temperature after PEB, and the deprotection reaction proceeds. In order to solve the PPD problem, one method is to perform high-temperature PEB using a protective group having a high activation energy. Since PPD is a room temperature reaction, the effect of PPD is reduced as the temperature gap with PEB increases. Using an acid generator that generates an acid having a bulky anion is also effective in reducing the influence of PPD. The proton that is an acid is paired with an anion, but proton hopping is reduced as the size of the anion increases.

  Another component that is expected to be effective in reducing the influence of PPD is a quencher. Conventional quencher development was aimed at improving the contrast of deprotection reaction by reducing acid diffusion in high-temperature PEB, but to reduce the influence of PPD, the viewpoint was changed. Development of a quencher that effectively suppresses acid diffusion at room temperature is desired.

JP 2001-194776 A JP 2002-226470 A JP 2002-363148 A Japanese Patent Laying-Open No. 2015-90382 JP 2010-84144 A International Publication No. 2015/111640

SPIE Vol. 5039 p1 (2003) SPIE Vol. 6520 p65203L-1 (2007) SPIE Vol. 7639 p76390W (2010)

  In order to suppress the influence of PPD, addition of a quencher is effective. However, in the case of a base generator that generates a super strong base described in Patent Documents 5 and 6, the place where the base is generated is an exposure region. Since acid diffusion in the resist film during standing at room temperature after PEB is diffusion of acid from the exposed part to the unexposed part, the quencher of the mechanism in which a basic substance is generated only in the exposed part is unexposed from the exposed part. It is not possible to prevent acid diffusion to the part.

  Quenchers such as amine quenchers, sulfonium salts of sulfonic acids and carboxylic acids, and iodonium salts are highly basic and have a high effect of suppressing acid diffusion in unexposed areas, but performance is still insufficient. It can suppress acid diffusion at room temperature more than quenchers such as amine quenchers, sulfonium salts and iodonium salts of sulfonic acids and carboxylic acids, and has a high dissolution contrast and a low edge roughness (LWR). Char development is desired.

  The present invention has been made in view of the above circumstances, a resist material having a high dissolution contrast in both a positive resist material and a negative resist material, a low LWR, and no dimensional change in a PPD, and this It is an object of the present invention to provide a pattern forming method using the above.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have used a predetermined phosphazene salt compound as a quencher, so that a resist having a low LWR, a high dissolution contrast, and no dimensional change even in PPD. The present inventors have found that a film can be obtained and completed the present invention.

［式中、Ｒ¹〜Ｒ⁷は、それぞれ独立に、水素原子、炭素数１〜２４の直鎖状、分岐状若しくは環状のアルキル基、炭素数２〜２４の直鎖状、分岐状若しくは環状のアルケニル基、炭素数２〜２４の直鎖状、分岐状若しくは環状のアルキニル基、又は炭素数６〜２０のアリール基であり、これらの中にエステル基、エーテル基、スルフィド基、スルホキシド基、カーボネート基、カーバメート基、スルホン基、ハロゲン原子、アミノ基、アミド基、ヒドロキシ基、チオール基、ニトロ基、又はハロゲン原子を含んでいてもよく、Ｒ¹とＲ²と、Ｒ²とＲ³と、Ｒ³とＲ⁴と、Ｒ⁴とＲ⁵と、Ｒ⁵とＲ⁶と、又はＲ⁶とＲ⁷とが結合して環を形成してもよく、Ｒ²とＲ³と、Ｒ⁴とＲ⁵と、又はＲ⁶とＲ⁷とが合体して二重結合を形成し、下記式（Ａ）−１で表される基を形成してもよく、Ｒ¹が下記式（Ａ）−２で表される基

（式中、Ｒ⁸〜Ｒ¹⁷は、それぞれ独立に、水素原子、炭素数１〜２４の直鎖状、分岐状若しくは環状のアルキル基、炭素数２〜２４の直鎖状、分岐状若しくは環状のアルケニル基、炭素数２〜２４の直鎖状、分岐状若しくは環状のアルキニル基、又は炭素数６〜２０のアリール基であり、Ｒ⁸とＲ⁹と、Ｒ⁹とＲ¹⁰と、Ｒ¹⁰とＲ¹¹と、Ｒ¹¹とＲ¹²と、Ｒ¹²とＲ¹³と、Ｒ¹⁴とＲ¹⁵と、又はＲ¹⁶とＲ¹⁷とが結合して環を形成してもよく、Ｒ⁸とＲ⁹と、Ｒ¹⁰とＲ¹¹と、又はＲ¹²とＲ¹³とが合体して二重結合を形成し、式（Ａ）−１で表される基を形成してもよい。）
であってもよい。Ａ^-は、水酸化物イオン、塩素イオン、臭素イオン、ヨウ素イオン、硝酸イオン、亜硝酸イオン、塩素酸イオン、亜塩素酸イオン、過塩素酸イオン、炭酸水素イオン、リン酸二水素イオン、硫酸水素イオン、チオシアン酸イオン、シュウ酸水素イオン、シアン化物イオン、ヨウ素酸イオン、又は下記式（Ｍ−１）若しくは（Ｍ−２）で表される陰イオンである。

（式中、Ｒ¹⁸は、水素原子、炭素数１〜３０の直鎖状、分岐状若しくは環状のアルキル基、炭素数２〜３０の直鎖状、分岐状若しくは環状のアルケニル基、炭素数２〜３０の直鎖状、分岐状若しくは環状のアルキニル基、炭素数６〜２０のアリール基、炭素数７〜２０のアラルキル基、又は炭素数３〜２０の芳香族若しくは脂肪族複素環含有基であり、これらの基の中にエステル基、エーテル基、スルフィド基、スルホキシド基、カーボネート基、カーバメート基、スルホン基、ハロゲン原子、アミノ基、アミド基、ヒドロキシ基、チオール基、ニトロ基、ハロゲン原子を含んでいてもよいが、Ｒ¹⁸は、下記式（Ａ）−３

（式中、Ａｒは、炭素数６〜１６の芳香族基であり、Ｒ²¹及びＲ²²は、それぞれ独立に、水素原子、ヒドロキシ基、アルコキシ基、炭素数１〜６の直鎖状、分岐状若しくは環状のアルキル基、又は炭素数６〜１０のアリール基である。）
で表される基は含まない。Ｒ¹⁹は、フッ素原子、炭素数１〜１０の直鎖状、分岐状若しくは環状のフッ素化アルキル基、又はフッ素化フェニル基であり、ヒドロキシ基、エーテル基、エステル基、アルコキシ基を含んでいてもよい。Ｒ²⁰は、水素原子、炭素数１〜１０の直鎖状、分岐状若しくは環状のアルキル基、炭素数２〜１０の直鎖状、分岐状若しくは環状のアルケニル基、炭素数２〜１０の直鎖状若しくは分岐状のアルキニル基、又は炭素数６〜１０のアリール基であり、ヒドロキシ基、エーテル基、エステル基、アルコキシ基を含んでいてもよい。）］
２．更に、スルホン酸、スルホンイミド又はスルホンメチドを発生する酸発生剤を含む１のレジスト材料。
３．更に、有機溶剤を含む１又は２のレジスト材料。
４．前記ベースポリマーが、下記式（ａ１）で表される繰り返し単位又は下記式（ａ２）で表される繰り返し単位を含むものである１〜３のいずれかのレジスト材料。

（式中、Ｒ³¹及びＲ³³は、それぞれ独立に、水素原子又はメチル基である。Ｒ³²及びＲ³⁴は、それぞれ独立に、酸不安定基である。Ｘは、単結合、エステル基、フェニレン基、ナフチレン基、又はラクトン環を含む炭素数１〜１２の連結基である。Ｙは、単結合又はエステル基である。）
５．更に、溶解阻止剤を含む４のレジスト材料。
６．化学増幅ポジ型レジスト材料である４又は５のレジスト材料。
７．前記ベースポリマーが、酸不安定基を含まないものである１〜３のいずれかのレジスト材料。
８．更に、架橋剤を含む７のレジスト材料。
９．化学増幅ネガ型レジスト材料である７又は８のレジスト材料。
１０．前記ベースポリマーが、更に下記式（ｆ１）〜（ｆ３）で表される繰り返し単位から選ばれる少なくとも１つの繰り返し単位を含む１〜９のいずれかのレジスト材料。

（式中、Ｒ⁵¹、Ｒ⁵⁵及びＲ⁵⁹は、それぞれ独立に、水素原子又はメチル基である。Ｒ⁵²は、単結合、フェニレン基、−Ｏ−Ｒ⁶³−又は−Ｃ(＝Ｏ)−Ｙ¹−Ｒ⁶³−であり、Ｙ¹は、−Ｏ−又は−ＮＨ−であり、Ｒ⁶³は、カルボニル基、エステル基、エーテル基若しくはヒドロキシ基を含んでいてもよい炭素数１〜６の直鎖状、分岐状若しくは環状の、アルキレン基若しくはアルケニレン基、又はフェニレン基である。Ｒ⁵³、Ｒ⁵⁴、Ｒ⁵⁶、Ｒ⁵⁷、Ｒ⁵⁸、Ｒ⁶⁰、Ｒ⁶¹及びＲ⁶²は、それぞれ独立に、カルボニル基、エステル基若しくはエーテル基を含んでいてもよい炭素数１〜１２の直鎖状、分岐状若しくは環状のアルキル基、又は炭素数６〜１２のアリール基、炭素数７〜２０のアラルキル基、若しくはメルカプトフェニル基である。Ａ¹は、単結合、−Ａ⁰−Ｃ(＝Ｏ)−Ｏ−、−Ａ⁰−Ｏ−又は−Ａ⁰−Ｏ−Ｃ(＝Ｏ)−であり、Ａ⁰は、カルボニル基、エステル基又はエーテル基を含んでいてもよい炭素数１〜１２の直鎖状、分岐状又は環状のアルキレン基である。Ａ²は、水素原子又はトリフルオロメチル基である。Ｚ¹は、単結合、メチレン基、エチレン基、フェニレン基、フッ素化されたフェニレン基、−Ｏ−Ｒ⁶⁴−又は−Ｃ(＝Ｏ)−Ｚ²−Ｒ⁶⁴−であり、Ｚ²は、−Ｏ−又は−ＮＨ−であり、Ｒ⁶⁴は、カルボニル基、エステル基、エーテル基若しくはヒドロキシ基を含んでいてもよい炭素数１〜６の直鎖状、分岐状若しくは環状の、アルキレン基若しくはアルケニレン基、又はフェニレン基、フッ素化されたフェニレン基、若しくはトリフルオロメチル基で置換されたフェニレン基である。Ｍ^-は、非求核性対向イオンを表す。ｆ１、ｆ２及びｆ３は、０≦ｆ１≦０.５、０≦ｆ２≦０.５、０≦ｆ３≦０.５、及び０＜ｆ１＋ｆ２＋ｆ３≦０.５を満たす正数である。）
１１．更に、界面活性剤を含む１〜１０のいずれかのレジスト材料。
１２．１〜１１のいずれかのレジスト材料を基板上に塗布する工程と、加熱処理後、高エネルギー線で露光する工程と、現像液を用いて現像する工程とを含むパターン形成方法。
１３．前記高エネルギー線が、波長１９３ｎｍのＡｒＦエキシマレーザー又は波長２４８ｎｍのＫｒＦエキシマレーザーである１２のパターン形成方法。
１４．前記高エネルギー線が、ＥＢ又は波長３〜１５ｎｍのＥＵＶである１２のパターン形成方法。 Accordingly, the present invention provides the following resist material and a pattern forming method using the resist material.
1. A resist material comprising a base polymer and a phosphazene salt compound represented by the following formula (A).

[Wherein, R ^{1 to} R ⁷ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 24 carbon atoms, a linear, branched or cyclic group having 2 to 24 carbon atoms. An alkenyl group, a linear, branched or cyclic alkynyl group having 2 to 24 carbon atoms, or an aryl group having 6 to 20 carbon atoms, among which an ester group, an ether group, a sulfide group, a sulfoxide group, It may contain a carbonate group, a carbamate group, a sulfone group, a halogen atom, an amino group, an amide group, a hydroxy group, a thiol group, a nitro group, or a halogen atom, and R ¹ and R ² , R ² and R ³ , , R ³ and R ⁴ , R ⁴ and R ⁵ , R ⁵ and R ⁶ , or R ⁶ and R ⁷ may combine to form a ring, and R ² , R ³ , R ⁴ and R ^5, or R ⁶ and and R ⁷ form a double bond coalesce the following formula (a) -1 It may form a group represented by a group R ¹ is represented by the following formula (A) -2

Wherein R ^{8 to} R ¹⁷ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 24 carbon atoms, a linear, branched or cyclic group having 2 to 24 carbon atoms. R ⁸ and R ⁹ , R ⁹ and R ¹⁰ , and R ¹⁰ , an alkenyl group having 2 to 24 carbon atoms, a linear, branched or cyclic alkynyl group having 2 to 24 carbon atoms, or an aryl group having 6 to 20 carbon atoms. , R ¹¹ , R ¹¹ and R ¹² , R ¹² and R ¹³ , R ¹⁴ and R ¹⁵ , or R ¹⁶ and R ¹⁷ may combine to form a ring, and R ⁸ and R ⁹ And R ¹⁰ and R ¹¹ or R ¹² and R ¹³ may be combined to form a double bond to form a group represented by the formula (A) -1.)
It may be. A ^- is hydroxide ion, chlorine ion, bromine ion, iodine ion, nitrate ion, nitrite ion, chlorate ion, chlorite ion, perchlorate ion, hydrogen carbonate ion, dihydrogen phosphate ion, sulfuric acid It is a hydrogen ion, a thiocyanate ion, a hydrogen oxalate ion, a cyanide ion, an iodate ion, or an anion represented by the following formula (M-1) or (M-2).

(In the formula, R ¹⁸ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 30 carbon atoms, or 2 carbon atoms. A linear, branched or cyclic alkynyl group of ˜30, an aryl group of 6 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an aromatic or aliphatic heterocyclic group containing 3 to 20 carbon atoms. There are ester group, ether group, sulfide group, sulfoxide group, carbonate group, carbamate group, sulfone group, halogen atom, amino group, amide group, hydroxy group, thiol group, nitro group, halogen atom in these groups. may comprise but, R ¹⁸ is represented by the following formula (A) -3

(In the formula, Ar is an aromatic group having 6 to 16 carbon atoms, and R ²¹ and R ²² are each independently a hydrogen atom, a hydroxy group, an alkoxy group, a straight chain having 1 to 6 carbon atoms, branched. Or a cyclic alkyl group or an aryl group having 6 to 10 carbon atoms.)
The group represented by is not included. R ¹⁹ is a fluorine atom, a linear, branched or cyclic fluorinated alkyl group having 1 to 10 carbon atoms, or a fluorinated phenyl group, and includes a hydroxy group, an ether group, an ester group, and an alkoxy group. Also good. R ²⁰ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 10 carbon atoms, and a straight chain having 2 to 10 carbon atoms. It is a chain or branched alkynyl group or an aryl group having 6 to 10 carbon atoms, and may contain a hydroxy group, an ether group, an ester group, or an alkoxy group. ]]
2. Furthermore, 1 resist material containing the acid generator which generate | occur | produces a sulfonic acid, a sulfonimide, or a sulfonemethide.
3. Furthermore, 1 or 2 resist material containing an organic solvent.
4). The resist material according to any one of 1 to 3, wherein the base polymer includes a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2).

Wherein R ³¹ and R ³³ are each independently a hydrogen atom or a methyl group. R ³² and R ³⁴ are each independently an acid labile group. X is a single bond, an ester group, (A phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms including a lactone ring. Y is a single bond or an ester group.)
5. Furthermore, 4 resist materials containing a dissolution inhibitor.
6). 4 or 5 resist material which is a chemically amplified positive resist material.
7). The resist material according to any one of 1 to 3, wherein the base polymer does not contain an acid labile group.
8). Furthermore, 7 resist materials containing a crosslinking agent.
9. 7 or 8 resist material which is a chemically amplified negative resist material.
10. The resist material according to any one of 1 to 9, wherein the base polymer further contains at least one repeating unit selected from repeating units represented by the following formulas (f1) to (f3).

(In the formula, R ⁵¹ , R ⁵⁵ and R ⁵⁹ each independently represents a hydrogen atom or a methyl group. R ⁵² represents a single bond, a phenylene group, —O—R ⁶³ — or —C (═O) —. Y ¹ —R ⁶³ —, Y ¹ is —O— or —NH—, and R ⁶³ has 1 to 6 carbon atoms which may contain a carbonyl group, an ester group, an ether group or a hydroxy group. A linear, branched or cyclic alkylene group, alkenylene group, or phenylene group, R ⁵³ , R ⁵⁴ , R ⁵⁶ , R ⁵⁷ , R ⁵⁸ , R ⁶⁰ , R ^61, and R ⁶² are each independently A linear, branched or cyclic alkyl group having 1 to 12 carbon atoms which may contain a carbonyl group, an ester group or an ether group, or an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. group, or .A ¹ is mercapto phenyl group, ^{Bond, -A 0 -C (= O)} -O -, - A 0 -O- or ^{-A 0 -O-C (= O} ) - and is, A ⁰ is a carbonyl group, an ester group or an ether group A C 1-12 linear, branched or cyclic alkylene group which may contain A ² is a hydrogen atom or a trifluoromethyl group, Z ¹ is a single bond, a methylene group, ethylene; Group, phenylene group, fluorinated phenylene group, —O—R ⁶⁴ — or —C (═O) —Z ² —R ⁶⁴ —, wherein Z ² is —O— or —NH—, R ⁶⁴ is a linear, branched or cyclic alkylene group or alkenylene group having 1 to 6 carbon atoms which may contain a carbonyl group, an ester group, an ether group or a hydroxy group, or a phenylene group, fluorinated Phenyl substituted with a phenylene group or trifluoromethyl group Is a group .M ^- is, .f1 represents a non-nucleophilic counter ion, f2 and f3 is, 0 ≦ f1 ≦ 0.5,0 ≦ f2 ≦ 0.5,0 ≦ f3 ≦ 0.5, and 0 <It is a positive number satisfying f1 + f2 + f3 ≦ 0.5.)
11. Furthermore, the resist material in any one of 1-10 containing surfactant.
12. A pattern forming method comprising a step of applying a resist material of any one of 12.1 to 11 on a substrate, a step of exposing to high energy rays after heat treatment, and a step of developing using a developer.
13. 12. The pattern forming method according to 12, wherein the high energy beam is an ArF excimer laser having a wavelength of 193 nm or a KrF excimer laser having a wavelength of 248 nm.
14 12. The pattern forming method according to 12, wherein the high energy ray is EB or EUV having a wavelength of 3 to 15 nm.

  Since the resist film containing the phosphazene salt compound has a high effect of suppressing acid diffusion and a high dissolution contrast, it is an excellent solution as a positive resist film, a negative resist film in alkali development, and a negative resist film in organic solvent development. It has image quality and a wide focus margin, has a small LWR, and does not cause dimensional changes even in the PPD.

[Resist material]
The resist material of the present invention includes a base polymer and a predetermined phosphazene salt compound. The phosphazene salt compound forms a salt by ion exchange with sulfonic acid, sulfonimide or sulfonemethide generated from an acid generator, particularly sulfonic acid, bissulfonimide or trissulfonemethide containing a fluorinated alkyl group. And release carboxylic acid or sulfonamide. Since the basicity of phosphazene is very high, it has a high effect of suppressing acid collection and acid diffusion. The phosphazene salt compound has no photosensitivity, does not generate phosphazene by light, and has an ability to supplement a sufficient acid even in an unexposed portion. Therefore, the diffusion of the acid from the exposed part to the unexposed part can be suppressed.

  In addition to the phosphazene salt compound, other amine compounds, ammonium salts, sulfonium salts, or iodonium salts may be separately added as a quencher to the resist material of the present invention. At this time, as the ammonium salt, sulfonium salt or iodonium salt added as the quencher, the sulfonium salt or iodonium salt of carboxylic acid, sulfonic acid, sulfonamide and saccharin is suitable. The carboxylic acid at this time may or may not be fluorinated at the α-position.

  The acid diffusion suppressing effect and contrast improving effect of the phosphazene salt compound are effective both in positive pattern formation and negative pattern formation by alkali development and in negative pattern formation in organic solvent development.

[Phosphazene salt compound]
The phosphazene salt compound contained in the resist material of the present invention is represented by the following formula (A).

（式中、Ｒ⁸〜Ｒ¹⁷は、それぞれ独立に、水素原子、炭素数１〜２４の直鎖状、分岐状若しくは環状のアルキル基、炭素数２〜２４の直鎖状、分岐状若しくは環状のアルケニル基、炭素数２〜２４の直鎖状、分岐状若しくは環状のアルキニル基、又は炭素数６〜２０のアリール基であり、Ｒ⁸とＲ⁹と、Ｒ⁹とＲ¹⁰と、Ｒ¹⁰とＲ¹¹と、Ｒ¹¹とＲ¹²と、Ｒ¹²とＲ¹³と、Ｒ¹⁴とＲ¹⁵と、又はＲ¹⁶とＲ¹⁷とが結合して環を形成してもよく、Ｒ⁸とＲ⁹と、Ｒ¹⁰とＲ¹¹と、又はＲ¹²とＲ¹³とが合体して二重結合を形成し、式（Ａ）−１で表される基を形成してもよい。）
であってもよい。 In formula (A), R ^{1 to} R ⁷ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 24 carbon atoms, a linear or branched chain having 2 to 24 carbon atoms. Or a cyclic alkenyl group, a linear, branched or cyclic alkynyl group having 2 to 24 carbon atoms, or an aryl group having 6 to 20 carbon atoms, among which an ester group, an ether group, a sulfide group, a sulfoxide Group, carbonate group, carbamate group, sulfone group, halogen atom, amino group, amide group, hydroxy group, thiol group, nitro group, or halogen atom, R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁴ and R ⁵ , R ⁵ and R ⁶ , or R ⁶ and R ⁷ may combine to form a ring, R ² and R ³ , R ⁴ and R ^5, or coalesce and R ⁶ and R ⁷ form a double bond, the following formula (a) May form a group represented by 1, a group R ¹ is represented by the following formula (A) -2

Wherein R ^{8 to} R ¹⁷ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 24 carbon atoms, a linear, branched or cyclic group having 2 to 24 carbon atoms. R ⁸ and R ⁹ , R ⁹ and R ¹⁰ , and R ¹⁰ , an alkenyl group having 2 to 24 carbon atoms, a linear, branched or cyclic alkynyl group having 2 to 24 carbon atoms, or an aryl group having 6 to 20 carbon atoms. , R ¹¹ , R ¹¹ and R ¹² , R ¹² and R ¹³ , R ¹⁴ and R ¹⁵ , or R ¹⁶ and R ¹⁷ may combine to form a ring, and R ⁸ and R ⁹ And R ¹⁰ and R ¹¹ or R ¹² and R ¹³ may be combined to form a double bond to form a group represented by the formula (A) -1.)
It may be.

［式中、Ｒ¹⁸は、水素原子、炭素数１〜３０の直鎖状、分岐状若しくは環状のアルキル基、炭素数２〜３０の直鎖状、分岐状若しくは環状のアルケニル基、炭素数２〜３０の直鎖状、分岐状若しくは環状のアルキニル基、炭素数６〜２０のアリール基、炭素数７〜２０のアラルキル基、又は炭素数３〜２０の芳香族若しくは脂肪族複素環含有基であり、これらの基の中にエステル基、エーテル基、スルフィド基、スルホキシド基、カーボネート基、カーバメート基、スルホン基、ハロゲン原子、アミノ基、アミド基、ヒドロキシ基、チオール基、ニトロ基、ハロゲン原子を含んでいてもよいが、Ｒ¹⁸は、下記式（Ａ）−３

（式中、Ａｒは、炭素数６〜１６の芳香族基であり、Ｒ²¹及びＲ²²は、それぞれ独立に、水素原子、ヒドロキシ基、アルコキシ基、炭素数１〜６の直鎖状、分岐状若しくは環状のアルキル基、又は炭素数６〜１０のアリール基である。）
で表される基は含まない。Ｒ¹⁹は、フッ素原子、炭素数１〜１０の直鎖状、分岐状若しくは環状のフッ素化アルキル基、又はフッ素化フェニル基であり、ヒドロキシ基、エーテル基、エステル基、アルコキシ基を含んでいてもよい。Ｒ¹⁰は、水素原子、炭素数１〜１０の直鎖状、分岐状若しくは環状のアルキル基、炭素数２〜１０の直鎖状、分岐状若しくは環状のアルケニル基、炭素数２〜１０の直鎖状若しくは分岐状のアルキニル基、又は炭素数６〜１０のアリール基であり、ヒドロキシ基、エーテル基、エステル基、アルコキシ基を含んでいてもよい。］ In formula (A), A ⁻ represents hydroxide ion, chlorine ion, bromine ion, iodine ion, nitrate ion, nitrite ion, chlorate ion, chlorite ion, perchlorate ion, bicarbonate ion, phosphorus ion It is an acid dihydrogen ion, hydrogen sulfate ion, thiocyanate ion, hydrogen oxalate ion, cyanide ion, iodate ion, or an anion represented by the following formula (M-1) or (M-2).

[Wherein, R ¹⁸ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 30 carbon atoms, or 2 carbon atoms. A linear, branched or cyclic alkynyl group of ˜30, an aryl group of 6 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an aromatic or aliphatic heterocyclic group containing 3 to 20 carbon atoms. There are ester group, ether group, sulfide group, sulfoxide group, carbonate group, carbamate group, sulfone group, halogen atom, amino group, amide group, hydroxy group, thiol group, nitro group, halogen atom in these groups. may comprise but, R ¹⁸ is represented by the following formula (A) -3

(In the formula, Ar is an aromatic group having 6 to 16 carbon atoms, and R ²¹ and R ²² are each independently a hydrogen atom, a hydroxy group, an alkoxy group, a straight chain having 1 to 6 carbon atoms, branched. Or a cyclic alkyl group or an aryl group having 6 to 10 carbon atoms.)
The group represented by is not included. R ¹⁹ is a fluorine atom, a linear, branched or cyclic fluorinated alkyl group having 1 to 10 carbon atoms, or a fluorinated phenyl group, and includes a hydroxy group, an ether group, an ester group, and an alkoxy group. Also good. R ¹⁰ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 10 carbon atoms, and a straight chain having 2 to 10 carbon atoms. It is a chain or branched alkynyl group or an aryl group having 6 to 10 carbon atoms, and may contain a hydroxy group, an ether group, an ester group, or an alkoxy group. ]

  Examples of the anion of the carboxylate represented by the formula (M-1) include, but are not limited to, the following.

  Examples of the anion of the sulfonamide salt represented by the formula (M-2) include, but are not limited to, the following.

  Examples of the cation of the phosphazene salt compound represented by the formula (A) include, but are not limited to, those shown below.

  The positive charge of the cationized phosphazene is delocalized in the phosphorus atom and the nitrogen atom surrounding it. For this reason, there are points where the anions of sulfonic acid, sulfonimide, and sulfonemethide are trapped and neutralized, so that the anions can be quickly trapped. Phosphazene is an excellent quencher that has a high trapping capacity in accordance with a high basicity.

  Examples of the synthesis method of the phosphazene salt compound represented by the formula (A) include a method of mixing phosphazene and carboxylic acid or sulfonamide.

  In the resist material of the present invention, the content of the phosphazene salt compound represented by the formula (A) is preferably 0.001 to 50 parts by mass with respect to 100 parts by mass of the base polymer in terms of sensitivity and acid diffusion suppression effect. 0.01 to 20 parts by mass is more preferable.

[Base polymer]
In the case of a positive resist material, the base polymer contained in the resist material of the present invention contains a repeating unit containing an acid labile group. As the repeating unit containing an acid labile group, a repeating unit represented by the following formula (a1) (hereinafter referred to as repeating unit a1) or a repeating unit represented by formula (a2) (hereinafter referred to as repeating unit a2). .) Is preferred.

In the formula, R ³¹ and R ³³ are each independently a hydrogen atom or a methyl group. R ³² and R ³⁴ are each independently an acid labile group. X is a single bond, an ester group, a phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms including a lactone ring, and is preferably a single bond, a phenylene group, or a naphthylene group. Y is a single bond or an ester group, but a single bond is preferred.

Examples of the repeating unit a1 include, but are not limited to, those shown below. In the following formulae, R ³¹ and R ³² are the same as described above.

The acid labile groups represented by R ³² and R ³⁴ in the repeating units a1 and a2 are variously selected. For example, the acid groups described in JP2013-80033A and JP2013-83821A can be used. Stabilizing groups can be used.

Typically, examples of the acid labile group include those represented by the following formulas (AL-1) to (AL-3).

In the formulas (AL-1) and (AL-2), R ³⁵ and R ³⁸ are monovalent hydrocarbon groups such as a linear, branched or cyclic alkyl group having 1 to 40 carbon atoms, particularly 1 to 20 carbon atoms. And may contain heteroatoms such as oxygen atom, sulfur atom, nitrogen atom and fluorine atom. R ³⁶ and R ³⁷ are each independently a hydrogen atom or a monovalent hydrocarbon group such as a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an oxygen atom, a sulfur atom, a nitrogen atom And may contain a hetero atom such as a fluorine atom. A1 is an integer of 0 to 10, particularly 1 to 5. R ³⁶ and R ³⁷ , R ³⁶ and R ³⁸ , or R ³⁷ and R ³⁸ are bonded to each other and together with the carbon atom or carbon atom and oxygen atom to which they are bonded, the number of carbon atoms is 3 to 20, preferably 4 to You may form 16 rings, especially an alicyclic ring.

In the formula (AL-3), R ³⁹ , R ⁴⁰ and R ⁴¹ are each independently a monovalent hydrocarbon group such as a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, and oxygen Hetero atoms, such as an atom, a sulfur atom, a nitrogen atom, and a fluorine atom, may be included. R ³⁹ and R ⁴⁰ , R ³⁹ and R ⁴¹ , or R ⁴⁰ and R ⁴¹ , together with the carbon atoms to which they are bonded, have 3 to 20 carbon atoms, preferably 4 to 16 carbon atoms, A ring may be formed.

  The base polymer may further contain a repeating unit b containing a phenolic hydroxy group as an adhesive group. Examples of the monomer that gives the repeating unit b include, but are not limited to, those shown below.

  The base polymer may further contain a repeating unit c containing a hydroxy group other than the phenolic hydroxy group, a lactone ring, an ether group, an ester group, a carbonyl group or a cyano group as another adhesive group. Examples of the monomer that gives the repeating unit c include, but are not limited to, those shown below.

  In the case of a monomer containing a hydroxy group, the hydroxy group may be replaced with an acetal group that can be easily deprotected with an acid such as an ethoxyethoxy group at the time of polymerization, and then deprotected with a weak acid and water after the polymerization, or an acetyl group, Substitution with a formyl group, pivaloyl group or the like, and alkali hydrolysis may be performed after polymerization.

  The base polymer may further include a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene, or derivatives thereof. Monomers that give the repeating unit d include, but are not limited to, those shown below.

  The base polymer may further contain a repeating unit e derived from styrene, vinyl naphthalene, vinyl anthracene, vinyl pyrene, methylene indan, vinyl pyridine or vinyl carbazole.

  The base polymer may further include a repeating unit f derived from an onium salt containing a polymerizable carbon-carbon double bond. Japanese Patent Application Laid-Open No. 2005-84365 proposes sulfonium salts and iodonium salts containing a polymerizable carbon-carbon double bond capable of generating a specific sulfonic acid. Japanese Patent Application Laid-Open No. 2006-178317 proposes a sulfonium salt in which a sulfonic acid is directly bonded to the main chain.

Preferable repeating unit f includes repeating units represented by the following formula (f1), (f2) or (f3) (hereinafter referred to as repeating unit f1, repeating unit f2, and repeating unit f3, respectively). The repeating units f1 to f3 may be used alone or in combination of two or more.

In the formula, R ⁵¹ , R ⁵⁵ and R ⁵⁹ are each independently a hydrogen atom or a methyl group. R ⁵² is a single bond, a phenylene group, —O—R ⁶³ — or —C (═O) —Y ¹ —R ⁶³ —, Y ¹ is —O— or —NH—, and R ⁶³ is , A carbonyl group, an ester group, an ether group, or a hydroxy group, which is a linear, branched or cyclic alkylene group, alkenylene group, or phenylene group having 1 to 6 carbon atoms. R ⁵³ , R ⁵⁴ , R ⁵⁶ , R ⁵⁷ , R ⁵⁸ , R ⁶⁰ , R ⁶¹ and R ⁶² are each independently a straight chain having 1 to 12 carbon atoms which may contain a carbonyl group, an ester group or an ether group. A chain, branched or cyclic alkyl group, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or a mercaptophenyl group. A ¹ represents a single ^{bond, -A 0 -C (= O)} -O -, - A 0 -O- or ^{-A 0 -O-C (= O} ) - and is, A ⁰ represents a carbonyl group, an ester It is a C1-C12 linear, branched or cyclic alkylene group which may contain a group or an ether group. A ² is a hydrogen atom or a trifluoromethyl group. Z ¹ is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, —O—R ⁶⁴ — or —C (═O) —Z ² —R ⁶⁴ —, and Z ² is —O— or —NH—, and R ⁶⁴ is a linear, branched or cyclic alkylene group having 1 to 6 carbon atoms which may contain a carbonyl group, an ester group, an ether group or a hydroxy group, or An alkenylene group, or a phenylene group, a phenylene group substituted with a fluorinated phenylene group, or a trifluoromethyl group. M ⁻ represents a non-nucleophilic counter ion. f1, f2, and f3 are positive numbers that satisfy 0 ≦ f1 ≦ 0.5, 0 ≦ f2 ≦ 0.5, 0 ≦ f3 ≦ 0.5, and 0 <f1 + f2 + f3 ≦ 0.5.

Examples of the monomer that gives the repeating unit f1 include, but are not limited to, those shown below. In the following formulae, M ⁻ represents a non-nucleophilic counter ion.

Non-nucleophilic counter ions represented by M ⁻ include halide ions such as chloride ions and bromide ions, fluoroalkyl sulfonates such as triflate, 1,1,1-trifluoroethanesulfonate, and nonafluorobutanesulfonate. Aryl sulfonates such as tosylate, benzene sulfonate, 4-fluorobenzene sulfonate, 1,2,3,4,5-pentafluorobenzene sulfonate, alkyl sulfonates such as mesylate and butane sulfonate, bis (trifluoromethylsulfonyl) imide, bis ( Examples thereof include sulfonimides such as perfluoroethylsulfonyl) imide and bis (perfluorobutylsulfonyl) imide, and sulfonemethides such as tris (trifluoromethylsulfonyl) methide and tris (perfluoroethylsulfonyl) methide.

The non-nucleophilic counter ion further includes a sulfonate ion in which the α-position represented by the following formula (K-1) is fluoro-substituted, and the α and β-positions represented by the following formula (K-2) are fluoro. Examples include substituted sulfonate ions.

In the formula (K-1), R ⁶⁵ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 20 carbon atoms. Or an aryl group having 6 to 20 carbon atoms and may contain an ether group, an ester group, a carbonyl group, a lactone ring or a fluorine atom.

In the formula (K-2), R ⁶⁶ is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic acyl group having 1 to 30 carbon atoms. , A linear, branched or cyclic alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, an ether group, an ester group, a carbonyl group, or It may contain a lactone ring.

Examples of the monomer that gives the repeating unit f2 include, but are not limited to, those shown below.

Monomers that give the repeating unit f3 include, but are not limited to, those shown below.

  By binding an acid generator to the polymer main chain, acid diffusion can be reduced, and degradation of resolution due to blurring of acid diffusion can be prevented. Further, the edge roughness is improved by uniformly dispersing the acid generator. In addition, when using the base polymer containing the at least 1 repeating unit chosen from repeating unit f1-f3, the mixing | blending of the photo-acid generator mentioned later can be abbreviate | omitted.

  As the base polymer for the positive resist material, the repeating unit a1 or a2 containing an acid labile group is essential. In this case, the content ratios of the repeating units a1, a2, b, c, d, e, f1, f2, and f3 are as follows: 0 ≦ a1 <1.0, 0 ≦ a2 <1.0, 0 <a1 + a2 <1.0. 0 ≦ b ≦ 0.9, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.8, 0 ≦ f1 ≦ 0.5, 0 ≦ f2 ≦ 0.5, and 0 ≦ f3 ≦ 0.5 is preferable, 0 ≦ a1 ≦ 0.9, 0 ≦ a2 ≦ 0.9, 0.1 ≦ a1 + a2 ≦ 0.9, 0 ≦ b ≦ 0.8, 0 ≦ c ≦ 0.5. 8, 0 ≦ d ≦ 0.7, 0 ≦ e ≦ 0.7, 0 ≦ f1 ≦ 0.4, 0 ≦ f2 ≦ 0.4, and 0 ≦ f3 ≦ 0.4, more preferably 0 ≦ a1 ≦ 0.8, 0 ≦ a2 ≦ 0.8, 0.1 ≦ a1 + a2 ≦ 0.8, 0 ≦ b ≦ 0.75, 0 ≦ c ≦ 0.75, 0 ≦ d ≦ 0.6, 0 ≦ e ≦ More preferred are 0.6, 0 ≦ f1 ≦ 0.3, 0 ≦ f2 ≦ 0.3, and 0 ≦ f3 ≦ 0.3. Note that a1 + a2 + b + c + d + e + f1 + f2 + f3 = 1.0.

  On the other hand, the base polymer for the negative resist material does not necessarily require an acid labile group. Examples of such a base polymer include those containing the repeating unit b and further containing repeating units c, d, e, f1, f2 and / or f3 as necessary. The content ratios of these repeating units are 0 <b ≦ 1.0, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.8, 0 ≦ f1 ≦ 0.5, 0 ≤ f2 ≤ 0.5 and 0 ≤ f3 ≤ 0.5, preferably 0.2 ≤ b ≤ 1.0, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.7, 0 ≤ e ≤ 0.7, 0 ≦ f1 ≦ 0.4, 0 ≦ f2 ≦ 0.4, and 0 ≦ f3 ≦ 0.4, more preferably 0.3 ≦ b ≦ 1.0, 0 ≦ c ≦ 0.75. 0 ≦ d ≦ 0.6, 0 ≦ e ≦ 0.6, 0 ≦ f1 ≦ 0.3, 0 ≦ f2 ≦ 0.3, and 0 ≦ f3 ≦ 0.3. Note that b + c + d + e + f1 + f2 + f3 = 1.0.

  In order to synthesize the base polymer, for example, the above-described monomer giving the repeating unit may be heated and polymerized in an organic solvent by adding a radical polymerization initiator.

  Examples of the organic solvent used at the time of polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, dioxane and the like. As polymerization initiators, 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2-azobis (2-methylpropionate) ), Benzoyl peroxide, lauroyl peroxide, and the like. The temperature during the polymerization is preferably 50 to 80 ° C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

  When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, acetoxystyrene or acetoxyvinylnaphthalene is used in place of hydroxystyrene or hydroxyvinylnaphthalene, and after polymerization, the acetoxy group is deprotected by alkaline hydrolysis and hydroxystyrene or hydroxyvinyl is used. Naphthalene may be used.

  Ammonia water, triethylamine, etc. can be used as the base during the alkali hydrolysis. Moreover, reaction temperature becomes like this. Preferably it is -20-100 degreeC, More preferably, it is 0-60 degreeC. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

  The base polymer has a polystyrene-equivalent weight average molecular weight (Mw) by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, preferably 1,000 to 500,000, more preferably 2,000 to 30,000. If Mw is too small, the resist material is inferior in heat resistance, and if it is too large, the alkali solubility is lowered, and the trailing phenomenon tends to occur after pattern formation.

  Furthermore, when the molecular weight distribution (Mw / Mn) is wide in the base polymer, there are low molecular weight or high molecular weight polymers, so that foreign matter is seen on the pattern after exposure or the shape of the pattern deteriorates. There is a risk. Since the influence of Mw and molecular weight distribution tends to increase as the pattern rule becomes finer, the molecular weight distribution of the base polymer is 1.0 to 2 in order to obtain a resist material suitably used for fine pattern dimensions. A narrow dispersion of 0.0, particularly 1.0 to 1.5 is preferable.

  The base polymer may include two or more polymers having different composition ratios, Mw, and molecular weight distribution.

[Acid generator]
By adding an acid generator to the resist material containing the phosphazene salt compound represented by formula (A) and the base polymer, it can function as a chemically amplified positive resist material or a chemically amplified negative resist material. Examples of the acid generator include compounds that generate an acid in response to actinic rays or radiation (photoacid generator). Any photoacid generator may be used as long as it is a compound that generates an acid upon irradiation with high energy rays, but a compound that generates sulfonic acid, sulfonimide, or sulfonemethide is preferable. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, and the like. Specific examples of the photoacid generator include those described in paragraphs [0122] to [0142] of JP-A-2008-111103.

Moreover, what is represented by following formula (1) or (2) can also be used suitably as a photo-acid generator.

In formula (1), R ¹⁰¹ , R ¹⁰² and R ¹⁰³ each independently represent a linear, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. . Further, any two of R ¹⁰¹ , R ¹⁰² and R ¹⁰³ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.

In the formula (1), X ⁻ represents an anion selected from the following formulas (1A) to (1D).

In the formula (1A), R ^fa represents a fluorine atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom.

As the anion represented by the formula (1A), those represented by the following formula (1A ′) are preferable.

In formula (1A ′), R ¹⁰⁴ represents a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R ¹⁰⁵ represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 38 carbon atoms which may contain a hetero atom. As said hetero atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, etc. are preferable, and an oxygen atom is more preferable. As the monovalent hydrocarbon group, those having 6 to 30 carbon atoms are particularly preferable from the viewpoint of obtaining high resolution in forming a fine pattern. Examples of the monovalent hydrocarbon group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, neopentyl, cyclopentyl, hexyl, and cyclohexyl. Group, 3-cyclohexenyl group, heptyl group, 2-ethylhexyl group, nonyl group, undecyl group, tridecyl group, pentadecyl group, heptadecyl group, 1-adamantyl group, 2-adamantyl group, 1-adamantylmethyl group, norbornyl group, Norbornylmethyl group, tricyclodecanyl group, tetracyclododecanyl group, tetracyclododecanylmethyl group, dicyclohexylmethyl group, icosanyl group, allyl group, benzyl group, diphenylmethyl group, tetrahydrofuryl group, methoxymethyl group, Ethoxymethyl group, methylthio Til group, acetamidomethyl group, trifluoroethyl group, (2-methoxyethoxy) methyl group, acetoxymethyl group, 2-carboxy-1-cyclohexyl group, 2-oxopropyl group, 4-oxo-1-adamantyl group, 3 -Oxocyclohexyl group etc. are mentioned. Further, some of the hydrogen atoms of these groups may be substituted with a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or between some of the carbon atoms of these groups. Hetero atom containing groups such as oxygen atom, sulfur atom and nitrogen atom may be interposed, and as a result, hydroxy group, cyano group, carbonyl group, ether group, ester group, sulfonate group, carbonate group, lactone ring , Sultone ring, carboxylic acid anhydride, haloalkyl group and the like.

  Regarding the synthesis of a sulfonium salt containing an anion represented by the formula (1A ′), JP2007-145797A, JP2008-106045A, JP2009-7327A, JP2009-258695A. It is detailed in etc. In addition, sulfonium salts described in JP2010-215608A, JP2012-41320A, JP2012-106986A, JP2012-153644A, and the like are also preferably used.

Examples of the sulfonium salt containing an anion represented by the formula (1A) include, but are not limited to, those shown below. In the following formulae, Ac represents an acetyl group, and Ph represents a phenyl group.

In formula (1B), R ^fb1 and R ^fb2 each independently represent a fluorine atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. Represent. Examples of the monovalent hydrocarbon group include the same ones as mentioned in the description of the R ^105. R ^fb1 and R ^fb2 are preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. R ^fb1 and R ^fb2 may be bonded to each other to form a ring together with a group (—CF ₂ —SO ₂ —N ⁻ —SO ₂ —CF ₂ —) to which they are bonded, and in particular, fluorinated ethylene Those forming a ring structure with a group or a fluorinated propylene group are preferred.

In formula (1C), R ^fc1 , R ^fc2 and R ^fc3 are each independently a linear, branched or cyclic monovalent carbon atom having 1 to 40 carbon atoms which may contain a fluorine atom or a hetero atom. Represents a hydrogen group. Examples of the monovalent hydrocarbon group include the same ones as mentioned in the description of the R ^105. R ^fc1 , R ^fc2 and R ^fc3 are preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. R ^fc1 and R ^fc2 may be bonded to each other to form a ring together with a group (—CF ₂ —SO ₂ —C ⁻ —SO ₂ —CF ₂ —) to which they are bonded, and in particular, fluorinated ethylene A group or a fluorinated propylene group that forms a ring structure is preferred.

In formula (1D), R ^fd represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. Examples of the monovalent hydrocarbon group include the same ones as mentioned in the description of the R ^105.

  The synthesis of a sulfonium salt containing an anion represented by the formula (1D) is detailed in JP 2010-215608 A and JP 2014-133723 A.

Examples of the sulfonium salt containing an anion represented by the formula (1D) include, but are not limited to, those shown below. In the following formulae, Ph represents a phenyl group.

  Note that the photoacid generator containing an anion represented by the formula (1D) does not have fluorine at the α-position of the sulfo group, but has two trifluoromethyl groups at the β-position. Thus, it has sufficient acidity to cleave the acid labile group in the resist polymer. Therefore, it can be used as a photoacid generator.

In formula (2), R ²⁰¹ and R ²⁰² each independently represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom. R ²⁰³ represents a linear, branched or cyclic divalent hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom. Further, any two of R ²⁰¹ , R ²⁰² and R ²⁰³ may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. L ^A represents a single bond, an ether group, or a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. X ^A , X ^B , X ^C and X ^D each independently represent a hydrogen atom, a fluorine atom or a trifluoromethyl group. However, at least one of X ^A , X ^B , X ^C and X ^D represents a substituent other than a hydrogen atom. k represents an integer of 0 to 3.

Examples of the monovalent hydrocarbon group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, t-pentyl group, n-pentyl group, and n-hexyl group. N-octyl group, n-nonyl group, n-decyl group, cyclopentyl group, cyclohexyl group, 2-ethylhexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group , Norbornyl group, oxanorbornyl group, tricyclo [5.2.1.0 ^2,6 ] decanyl group, adamantyl group, phenyl group, naphthyl group, anthracenyl group and the like. In addition, a part of hydrogen atoms of these groups may be substituted with a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or a part of carbon atoms is an oxygen atom, sulfur May be substituted with a heteroatom-containing group such as an atom or a nitrogen atom, and as a result, a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, It may contain a carboxylic acid anhydride, a haloalkyl group, or the like.

  Examples of the divalent hydrocarbon group include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. , Heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1, 12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group, etc. Linear alkanediyl group of the above; saturated cyclic divalent hydrocarbon group such as cyclopentanediyl group, cyclohexanediyl group, norbornanediyl group and adamantanediyl group; unsaturated cyclic group such as phenylene group and naphthylene group Valent hydrocarbon group, and the like. Moreover, some hydrogen atoms of these groups may be substituted with an alkyl group such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a t-butyl group. Further, some of the hydrogen atoms of these groups may be substituted with a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or between some of the carbon atoms of these groups. Hetero atom containing groups such as oxygen atom, sulfur atom and nitrogen atom may be interposed, and as a result, hydroxy group, cyano group, carbonyl group, ether group, ester group, sulfonate group, carbonate group, lactone ring , Sultone ring, carboxylic acid anhydride, haloalkyl group and the like. As the heteroatom, an oxygen atom is preferable.

As a photo-acid generator represented by Formula (2), what is represented by following formula (2 ') is preferable.

In the formula (2 ′), L ^A is the same as described above. R represents a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R ³⁰¹ , R ³⁰² and R ³⁰³ each independently represent a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. Examples of the monovalent hydrocarbon group include the same ones as mentioned in the description of the R ^105. x and y each independently represents an integer of 0 to 5, and z represents an integer of 0 to 4.

Examples of the photoacid generator represented by formula (2) include, but are not limited to, those shown below. In the following formulae, R is the same as described above, and Me represents a methyl group.

  Among the photoacid generators, those containing an anion represented by the formula (1A ′) or (1D) are particularly preferable because of low acid diffusion and excellent solubility in a resist solvent. Moreover, the thing containing the anion represented by Formula (2 ') has a very small acid diffusion, and is especially preferable.

  0.1-50 mass parts is preferable with respect to 100 mass parts of base polymers, and, as for the compounding quantity of an acid generator, 1-40 mass parts is more preferable.

[Other ingredients]
A chemically amplified positive resist material or a chemically amplified negative resist material containing a phosphazene salt compound represented by formula (A), a base polymer and an acid generator, and an organic solvent, a surfactant, a dissolution inhibitor, a crosslinking agent, etc. The composition of the positive resist material and the negative resist material is appropriately combined according to the purpose to constitute a positive resist material and a negative resist material, so that the dissolution rate of the base polymer in the developing solution is accelerated by a catalytic reaction in the exposed portion. A positive resist material and a negative resist material can be used. In this case, the resist film has a high dissolution contrast and resolution, an exposure margin, excellent process adaptability, and good pattern shape after exposure. From these facts, it is highly practical and can be very effective as a resist material for VLSI. In particular, when a chemically amplified positive resist material containing an acid generator and utilizing an acid catalyzed reaction is used, the sensitivity can be increased, and various characteristics are further improved and extremely useful. .

  In the case of a positive resist material, by adding a dissolution inhibitor, the difference in dissolution rate between the exposed area and the unexposed area can be further increased, and the resolution can be further improved. In the case of a negative resist material, a negative pattern can be obtained by adding a crosslinking agent to lower the dissolution rate of the exposed portion.

  Examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, and methyl-2-n-pentyl ketone described in paragraphs [0144] to [0145] of JP-A-2008-111103, 3-methoxybutanol, Alcohols such as 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether , Ethers such as propylene glycol dimethyl ether and diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, lactic acid Esters such as chill, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, t-butyl acetate, t-butyl propionate, propylene glycol mono t-butyl ether acetate, γ-butyrolactone, etc. Lactones, and mixed solvents thereof.

  The blending amount of the organic solvent is preferably 100 to 10,000 parts by mass and more preferably 200 to 8,000 parts by mass with respect to 100 parts by mass of the base polymer.

  Examples of the surfactant include those described in paragraphs [0165] to [0166] of JP-A-2008-111103. By adding a surfactant, the coating property of the resist material can be further improved or controlled. The blending amount of the surfactant is preferably 0.0001 to 10 parts by mass with respect to 100 parts by mass of the base polymer.

  The dissolution inhibitor is preferably a compound having a molecular weight of 100 to 1,000, more preferably 150 to 800, and a hydrogen atom of the phenolic hydroxy group of a compound having two or more phenolic hydroxy groups in the molecule. A compound substituted with a labile group as a whole in a proportion of 0 to 100 mol%, or a proportion of an average of 50 to 100 mol% of hydrogen atoms of the carboxyl group of a compound containing a carboxyl group in the molecule as a whole with an acid labile group And a compound substituted with. Specific examples include bisphenol A, trisphenol, phenolphthalein, cresol novolac, naphthalene carboxylic acid, adamantane carboxylic acid, hydroxy group of cholic acid, and a compound in which the hydrogen atom of carboxyl group is substituted with an acid labile group. For example, it describes in paragraph [0155]-[0178] of Unexamined-Japanese-Patent No. 2008-122932.

  In the case of a positive resist material, the blending amount of the dissolution inhibitor is preferably 0 to 50 parts by mass and more preferably 5 to 40 parts by mass with respect to 100 parts by mass of the base polymer.

  As a crosslinking agent, an epoxy compound, a melamine compound, a guanamine compound, a glycoluril compound or a urea compound, an isocyanate compound, an azide compound substituted with at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group, Examples thereof include compounds containing a double bond such as an alkenyl ether group. These may be used as additives, but may be introduced as pendant groups in the polymer side chain. A compound containing a hydroxy group can also be used as a crosslinking agent.

  Examples of the epoxy compound include tris (2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, triethylolethane triglycidyl ether, and the like.

  Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are methoxymethylated or a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, hexamethylol melamine And a compound in which 1 to 6 methylol groups are acyloxymethylated or a mixture thereof.

  Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which 1 to 4 methylol groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine. A compound in which ˜4 methylol groups are acyloxymethylated or a mixture thereof is exemplified.

  Examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxyglycoluril, tetramethoxymethylglycoluril, a compound in which 1 to 4 methylol groups of tetramethylolglycoluril are methoxymethylated, or a mixture thereof, and tetramethylolglycoluril methylol. Examples thereof include compounds in which 1 to 4 of the groups are acyloxymethylated or mixtures thereof. Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, a compound in which 1 to 4 methylol groups of tetramethylol urea are methoxymethylated, a mixture thereof, tetramethoxyethyl urea, and the like.

  Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

  Examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide, 4,4′-methylidenebisazide, and 4,4′-oxybisazide.

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

  In the case of a negative resist material, the blending amount of the crosslinking agent is preferably 0.1 to 50 parts by mass, and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the base polymer.

  The resist material of the present invention may contain a quencher other than the phosphazene salt compound represented by the formula (A) (hereinafter referred to as other quencher). Other quenchers include conventional basic compounds. Conventional basic compounds include primary, secondary, and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, and sulfonyl groups. Nitrogen-containing compounds having a hydroxy group, nitrogen-containing compounds having a hydroxy group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, carbamates and the like. In particular, primary, secondary, and tertiary amine compounds described in paragraphs [0146] to [0164] of JP-A-2008-111103, particularly hydroxy groups, ether groups, ester groups, lactone rings, An amine compound having a cyano group or a sulfonate group or a compound having a carbamate group described in Japanese Patent No. 3790649 is preferred. By adding such a basic compound, for example, the acid diffusion rate in the resist film can be further suppressed, or the shape can be corrected.

  Other quenchers include onium salts such as sulfonium salts, iodonium salts and ammonium salts of sulfonic acids and carboxylic acids which are not fluorinated at the α-position described in JP-A-2008-158339. . A sulfonic acid, sulfonimide or sulfonemethide fluorinated at the α-position is necessary to deprotect the acid labile group of the carboxylic acid ester, but by salt exchange with an onium salt which is not fluorinated at the α-position. A sulfonic acid or carboxylic acid which is not fluorinated at the α-position is released. The sulfonic acid and carboxylic acid in which the α-position is not fluorinated does not cause a deprotection reaction, and thus functions as a quencher.

  Examples of other quenchers include polymer quenchers described in JP-A-2008-239918. This enhances the rectangularity of the patterned resist by being oriented on the coated resist surface. The polymer quencher also has an effect of preventing pattern film loss and pattern top rounding when a protective film for immersion exposure is applied.

  The amount of other quenchers to be blended is preferably 0 to 5 parts by mass, more preferably 0 to 4 parts by mass with respect to 100 parts by mass of the base polymer.

  The resist material of the present invention may contain a polymer compound (water repellency improver) for improving the water repellency of the resist surface after spin coating. The water repellency improver can be used in immersion lithography that does not use a top coat. The water repellency improver is preferably a polymer compound containing a fluorinated alkyl group or a polymer compound containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue having a specific structure. Examples are disclosed in Japanese Unexamined Patent Application Publication Nos. 2007-297590 and 2008-111103. The water repellency improver needs to be dissolved in an organic solvent developer. The above-mentioned water repellency improver having a specific 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in a developer. As a water repellency improver, a polymer compound containing a repeating unit containing an amino group or an amine salt has a high effect of preventing evaporation of an acid in PEB and preventing poor opening of a hole pattern after development. The blending amount of the water repellency improver is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the base polymer.

  Acetylene alcohols can also be blended in the resist material of the present invention. Examples of the acetylene alcohols include those described in paragraphs [0179] to [0182] of JP-A-2008-122932. As for the compounding quantity of acetylene alcohol, 0-5 mass parts is preferable with respect to 100 mass parts of base polymers.

[Pattern formation method]
When the resist material of the present invention is used for manufacturing various integrated circuits, a known lithography technique can be applied.

For example, the positive resist material of the present invention is applied to a substrate for manufacturing an integrated circuit (Si, SiO ₂ , SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflection film, etc.) or a substrate for manufacturing a mask circuit (Cr , CrO, CrON, MoSi ₂
Etc.) is applied so as to have a coating film thickness of 0.1 to 2.0 μm by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating or the like. This is preferably pre-baked on a hot plate at 60 to 150 ° C. for 10 seconds to 30 minutes, more preferably at 80 to 120 ° C. for 30 seconds to 20 minutes. Next, the target pattern is exposed through a predetermined mask or directly with high energy rays such as ultraviolet rays, far ultraviolet rays, EB, EUV, X-rays, soft X-rays, excimer laser, γ rays, synchrotron radiation and the like. The exposure dose, 1 to 200 mJ / cm ² or so, in particular 10 to 100 mJ / cm ^2, or 0.1~100μC / cm ² or so, it is preferable that exposure to particular a 0.5~50μC / cm ^2. Next, PEB is preferably performed on a hot plate at 60 to 150 ° C. for 10 seconds to 30 minutes, more preferably at 80 to 120 ° C. for 30 seconds to 20 minutes.

  Further, 0.1 to 10% by mass, preferably 2 to 5% by mass of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide ( Development is carried out using a developing solution of an alkaline aqueous solution such as TBAH) for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, by a conventional method such as a dip method, a paddle method, or a spray method. As a result, the irradiated portion is dissolved in the developer, and the unexposed portion is not dissolved, and a desired positive pattern is formed on the substrate. In the case of a negative resist, it is the opposite of that in the case of a positive resist, that is, the portion irradiated with light is insoluble in the developer, and the portion not exposed is dissolved. The resist material of the present invention is particularly suitable for fine patterning by KrF excimer laser, ArF excimer laser, EB, EUV, X-ray, soft X-ray, γ-ray, and synchrotron radiation among high energy rays.

  Using a positive resist material containing a base polymer containing an acid labile group, negative development can be performed to obtain a negative pattern by organic solvent development. The developer used at this time is 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate. , Butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, methyl propionate , Ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, 2-hydroxy Ethyl isobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. Is mentioned. These organic solvents may be used alone or in combination of two or more.

  At the end of development, rinse is performed. As the rinsing liquid, a solvent which is mixed with the developer and does not dissolve the resist film is preferable. As such a solvent, alcohols having 3 to 10 carbon atoms, ether compounds having 8 to 12 carbon atoms, alkanes having 6 to 12 carbon atoms, alkenes, alkynes, and aromatic solvents are preferably used.

  Specifically, as alcohol having 3 to 10 carbon atoms, n-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, t-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, t-pentyl 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-ethyl-1-butanol, 2-methyl-1-pen Tanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl 1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pen Examples include butanol, cyclohexanol, 1-octanol and the like.

  Examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-s-butyl ether, di-n-pentyl ether, diisopentyl ether, di-s-pentyl ether, and di-t-pentyl. One or more kinds of solvents selected from ether and di-n-hexyl ether are exemplified.

  Examples of the alkane having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. It is done. Examples of the alkene having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Examples of the alkyne having 6 to 12 carbon atoms include hexyne, heptin, octyne and the like.

  Examples of the aromatic solvent include toluene, xylene, ethylbenzene, isopropylbenzene, t-butylbenzene, mesitylene and the like.

  By performing the rinsing, it is possible to reduce the collapse of the resist pattern and the occurrence of defects. Moreover, rinsing is not always essential, and the amount of solvent used can be reduced by not rinsing.

  The hole pattern or trench pattern after development can be shrunk by thermal flow, RELACS technology or DSA technology. A shrink agent is applied onto the hole pattern, and the crosslinking of the shrink agent occurs on the surface of the resist due to the diffusion of the acid catalyst from the resist layer during baking, and the shrink agent adheres to the sidewall of the hole pattern. The baking temperature is preferably 70 to 180 ° C., more preferably 80 to 170 ° C., and the time is preferably 10 to 300 seconds, so that the excess shrink agent is removed and the hole pattern is reduced.

  EXAMPLES Hereinafter, although a synthesis example, an Example, and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following Example.

  The structures of quenchers 1 to 13 made of a phosphazene salt compound used in the resist material of the present invention are shown below. The quenchers 1 to 13 were synthesized by mixing a phosphazene compound that gives the following cation and a carboxylic acid, sulfonimide, nitric acid, hydrochloric acid, or hydroiodic acid that gives the following anion.

[Synthesis Example] Synthesis of polymer compound (Polymers 1 to 6) Each monomer is combined and subjected to a copolymerization reaction in a tetrahydrofuran solvent, crystallized in methanol, further washed with hexane, isolated and dried. The polymer compounds (Polymers 1 to 6) having the following composition were obtained. The composition of the obtained polymer compound was confirmed by ¹ H-NMR, and Mw and dispersity (Mw / Mn) were confirmed by gel permeation chromatography (solvent: tetrahydrofuran (THF), standard: polystyrene).

[Examples and Comparative Examples]
A solution in which each component is dissolved in the composition shown in Tables 1 and 2 in a solvent in which 100 ppm of FC-4430 manufactured by Sumitomo 3M Co., Ltd. as a surfactant is dissolved, is filtered through a 0.2 μm size filter and positive. Type resist material and negative type resist material were prepared.
In Tables 1 and 2, each composition is as follows.
Polymers 1 to 6 (see the above structural formula)
Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)
GBL (γ-butyrolactone)
CyH (cyclohexanone)
CyP (cyclopentanone)
PGME (propylene glycol monomethyl ether)

Acid generator: PAG1-3 (see the following structural formula)

Comparative quenchers 1 to 5 (see structural formula below)

Water repellent polymer 1 (see structural formula below)

[ArF immersion exposure evaluation]
[Examples 1-1 to 1-14, Comparative Examples 1-1 to 1-5]
The resist material shown in Table 1 is a silicon wafer with a spin-on carbon film ODL-102 (carbon content of 80% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. 200 nm, and a silicon-containing spin-on hard mask SHB-A940 (silicon The film was spin-coated on a substrate for a trilayer process having a film thickness of 35 nm, and baked at 100 ° C. for 60 seconds using a hot plate, so that the resist film had a thickness of 80 nm. . Using ArF excimer laser scanner (Nikon Corporation NSR-S610C, NA1.30, σ0.98 / 0.78, 35 degree cross pole illumination, Azimuthally polarized illumination, 6% halftone phase shift mask) on the wafer Exposure is performed using a mask having dimensions of 60 nm line and 200 nm pitch, PEB is performed for 60 seconds at the temperature shown in Table 1, and development is continuously performed for 30 seconds with n-butyl acetate. Dimensions are 60 nm space, 200 nm pitch. A negative pattern of the trench was formed. Next, the exposure and PEB were performed in the same manner, and the wafer was stored in FOUP at 23 ° C. for 24 hours and then developed with n-butyl acetate for 30 seconds to form a negative pattern of trenches with a pitch of 200 nm. The length of the trench pattern was measured with a length measuring SEM (CG-4000) manufactured by Hitachi High-Technologies Corporation. From the dimensions of the trench pattern continuously formed until development, the trench pattern formed by standing for 24 hours after PEB was measured. The value obtained by subtracting the dimension was defined as the PPD dimension. The results are shown in Table 1.

[EB drawing evaluation]
[Examples 2-1 to 2-5, Comparative examples 2-1 to 2-5]
The resist materials shown in Table 2 were spin coated on a hexamethyldisilazane vapor primed Si substrate and prebaked at 110 ° C. for 60 seconds using a hot plate to prepare an 80 nm resist film. To this, drawing was performed in a vacuum chamber at an acceleration voltage of 50 kV using HL-800D manufactured by Hitachi, Ltd. Immediately after drawing, PEB was performed on a hot plate at 90 ° C. for 60 seconds, and development was performed with an aqueous solution of 2.38% by mass of tetramethylammonium hydroxide for 30 seconds to obtain a pattern.
The following evaluation was performed about the obtained resist pattern.
In the case of a positive resist film, the minimum trench size at an exposure amount that resolves a 120 nm trench according to the size was defined as the resolving power. In the case of a negative resist film, the resolution was defined as the minimum isolated line size at the exposure amount for resolving the 120 nm isolated line according to the size. In addition, Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-3 and 2-5 are positive resist materials, and Examples 2-5 and Comparative Examples 2-4 are negative resist materials.
The results are shown in Table 2.

  From the results shown in Tables 1 and 2, it was found that the resist material containing the phosphazene salt compound of the present invention was excellent in dimensional stability in PPD, and had sufficient resolution and LWR.

Claims (14)

A resist material comprising a base polymer and a phosphazene salt compound represented by the following formula (A).

[Wherein, R ^{1 to} R ⁷ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 24 carbon atoms, a linear, branched or cyclic group having 2 to 24 carbon atoms. An alkenyl group, a linear, branched or cyclic alkynyl group having 2 to 24 carbon atoms, or an aryl group having 6 to 20 carbon atoms, among which an ester group, an ether group, a sulfide group, a sulfoxide group, It may contain a carbonate group, a carbamate group, a sulfone group, a halogen atom, an amino group, an amide group, a hydroxy group, a thiol group, a nitro group, or a halogen atom, and R ¹ and R ² , R ² and R ³ , , R ³ and R ⁴ , R ⁴ and R ⁵ , R ⁵ and R ⁶ , or R ⁶ and R ⁷ may combine to form a ring, and R ² , R ³ , R ⁴ and R ^5, or R ⁶ and and R ⁷ form a double bond coalesce the following formula (a) -1 It may form a group represented by a group R ¹ is represented by the following formula (A) -2

Wherein R ^{8 to} R ¹⁷ are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 24 carbon atoms, a linear, branched or cyclic group having 2 to 24 carbon atoms. R ⁸ and R ⁹ , R ⁹ and R ¹⁰ , and R ¹⁰ , an alkenyl group having 2 to 24 carbon atoms, a linear, branched or cyclic alkynyl group having 2 to 24 carbon atoms, or an aryl group having 6 to 20 carbon atoms. , R ¹¹ , R ¹¹ and R ¹² , R ¹² and R ¹³ , R ¹⁴ and R ¹⁵ , or R ¹⁶ and R ¹⁷ may combine to form a ring, and R ⁸ and R ⁹ And R ¹⁰ and R ¹¹ or R ¹² and R ¹³ may be combined to form a double bond to form a group represented by the formula (A) -1.)
It may be. A ^- is hydroxide ion, chlorine ion, bromine ion, iodine ion, nitrate ion, nitrite ion, chlorate ion, chlorite ion, perchlorate ion, hydrogen carbonate ion, dihydrogen phosphate ion, sulfuric acid It is a hydrogen ion, a thiocyanate ion, a hydrogen oxalate ion, a cyanide ion, an iodate ion, or an anion represented by the following formula (M-1) or (M-2).

(In the formula, R ¹⁸ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 30 carbon atoms, or 2 carbon atoms. A linear, branched or cyclic alkynyl group of ˜30, an aryl group of 6 to 20 carbon atoms, an aralkyl group of 7 to 20 carbon atoms, or an aromatic or aliphatic heterocyclic group containing 3 to 20 carbon atoms. There are ester group, ether group, sulfide group, sulfoxide group, carbonate group, carbamate group, sulfone group, halogen atom, amino group, amide group, hydroxy group, thiol group, nitro group, halogen atom in these groups. may comprise but, R ¹⁸ is represented by the following formula (A) -3

(In the formula, Ar is an aromatic group having 6 to 16 carbon atoms, and R ²¹ and R ²² are each independently a hydrogen atom, a hydroxy group, an alkoxy group, a straight chain having 1 to 6 carbon atoms, branched. Or a cyclic alkyl group or an aryl group having 6 to 10 carbon atoms.)
The group represented by is not included. R ¹⁹ is a fluorine atom, a linear, branched or cyclic fluorinated alkyl group having 1 to 10 carbon atoms, or a fluorinated phenyl group, and includes a hydroxy group, an ether group, an ester group, and an alkoxy group. Also good. R ²⁰ represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 10 carbon atoms, and a straight chain having 2 to 10 carbon atoms. It is a chain or branched alkynyl group or an aryl group having 6 to 10 carbon atoms, and may contain a hydroxy group, an ether group, an ester group, or an alkoxy group. ]]   The resist material according to claim 1, further comprising an acid generator that generates sulfonic acid, sulfonimide, or sulfonemethide.   The resist material according to claim 1 or 2, further comprising an organic solvent. The resist material according to claim 1, wherein the base polymer includes a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2).

Wherein R ³¹ and R ³³ are each independently a hydrogen atom or a methyl group. R ³² and R ³⁴ are each independently an acid labile group. X is a single bond, an ester group, (A phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms including a lactone ring. Y is a single bond or an ester group.)   The resist material according to claim 4, further comprising a dissolution inhibitor.   6. The resist material according to claim 4, which is a chemically amplified positive resist material.   The resist material according to claim 1, wherein the base polymer does not contain an acid labile group.   Furthermore, the resist material of Claim 7 containing a crosslinking agent.   The resist material according to claim 7 or 8, which is a chemically amplified negative resist material. The resist material according to claim 1, wherein the base polymer further contains at least one repeating unit selected from repeating units represented by the following formulas (f1) to (f3).

(In the formula, R ⁵¹ , R ⁵⁵ and R ⁵⁹ each independently represents a hydrogen atom or a methyl group. R ⁵² represents a single bond, a phenylene group, —O—R ⁶³ — or —C (═O) —. Y ¹ —R ⁶³ —, Y ¹ is —O— or —NH—, and R ⁶³ has 1 to 6 carbon atoms which may contain a carbonyl group, an ester group, an ether group or a hydroxy group. A linear, branched or cyclic alkylene group, alkenylene group, or phenylene group, R ⁵³ , R ⁵⁴ , R ⁵⁶ , R ⁵⁷ , R ⁵⁸ , R ⁶⁰ , R ^61, and R ⁶² are each independently A linear, branched or cyclic alkyl group having 1 to 12 carbon atoms which may contain a carbonyl group, an ester group or an ether group, or an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. group, or .A ¹ is mercapto phenyl group, ^{Bond, -A 0 -C (= O)} -O -, - A 0 -O- or ^{-A 0 -O-C (= O} ) - and is, A ⁰ is a carbonyl group, an ester group or an ether group A C 1-12 linear, branched or cyclic alkylene group which may contain A ² is a hydrogen atom or a trifluoromethyl group, Z ¹ is a single bond, a methylene group, ethylene; Group, phenylene group, fluorinated phenylene group, —O—R ⁶⁴ — or —C (═O) —Z ² —R ⁶⁴ —, wherein Z ² is —O— or —NH—, R ⁶⁴ is a linear, branched or cyclic alkylene group or alkenylene group having 1 to 6 carbon atoms which may contain a carbonyl group, an ester group, an ether group or a hydroxy group, or a phenylene group, fluorinated Phenyl substituted with a phenylene group or trifluoromethyl group Is a group .M ^- is, .f1 represents a non-nucleophilic counter ion, f2 and f3 is, 0 ≦ f1 ≦ 0.5,0 ≦ f2 ≦ 0.5,0 ≦ f3 ≦ 0.5, and 0 <It is a positive number satisfying f1 + f2 + f3 ≦ 0.5.)   Furthermore, the resist material of any one of Claims 1-10 containing surfactant.   A pattern forming method comprising: a step of applying the resist material according to any one of claims 1 to 11 on a substrate; a step of exposing to high energy rays after heat treatment; and a step of developing using a developer. .   The pattern formation method according to claim 12, wherein the high energy beam is an ArF excimer laser having a wavelength of 193 nm or a KrF excimer laser having a wavelength of 248 nm.   The pattern forming method according to claim 12, wherein the high energy beam is an electron beam or extreme ultraviolet rays having a wavelength of 3 to 15 nm.