JP2008096717A - Chemically amplified positive photoresist composition for low-temperature dry etching and photoresist pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemically amplified positive photoresist composition which satisfies the following conditions (1)-(4); (1) it does not cause cracking due to a thermal shock even when exposed to a low temperature of ≤0°C, (2) it can form a thick film of ≥5 μm, (3) it has high sensitivity, and (4) it can easily be stripped with a common solvent. <P>SOLUTION: The chemically amplified positive photoresist composition for low-temperature dry etching comprises (A) a photoacid generator, (B) a resin component and (C) an organic solvent. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a chemically amplified positive photoresist composition for dry etching at a low temperature suitable for a dry etching process under low temperature conditions in the manufacture of a MEMS device and a through electrode, and a photoresist pattern formation using the same Regarding the method.

  Micro-Electro-Mechanical Systems (MEMS) elements, and small machines (micromachines) incorporating MEMS elements, as well as through electrodes for high-density mounting, have a high aspect ratio (hole depth). A silicon substrate that has been processed with a thickness / opening diameter) is required, and a lithography method using a photoresist composition is used for processing the silicon substrate.

  Conventionally, a normal photoresist composition used in a lithography method has low resistance to dry etching of a photoresist composition. Therefore, a high aspect ratio silicon substrate has been formed by repeating a lithography process. However, the process of repeating this process naturally has a poor yield, and it is inevitable that the amount of chemicals such as photoresist increases and the cost increases. Furthermore, there are problems such as unevenness on the side wall of the pattern or accumulation of residue at the bottom of the processed substrate.

  Recently, in order to obtain a high etching rate characteristic of a silicon substrate, a method of performing a dry etching process at a low temperature of 0 ° C. or less has been studied. However, such a low temperature process has a large load on a photoresist pattern. Thus, due to the temperature change (thermal shock) of the photoresist pattern, problems such as difficulty in peeling of the photoresist pattern, cracks in the photoresist pattern, and deterioration in the dimensional accuracy of the photoresist pattern occur.

  In order to suitably form a silicon substrate under such a low temperature condition, the following characteristics are required for the photoresist composition. That is, (1) no cracks due to thermal shock are generated even when exposed to a low temperature of 0 ° C. or lower (having crack resistance), and (2) a deep etching process of 50 μm or more on the silicon substrate. It is possible to form a thick film of 5 μm or more, (3) high sensitivity so as not to cause insufficient sensitivity because it is a thick film resist, and (4) easy peeling with a general solvent. Is required.

  Further, with respect to conventional thick film forming photoresists, a positive photosensitive resin composition having a quinonediazide group-containing compound used for forming a pump or wiring is disclosed (Patent Document 1).

Furthermore, various positive chemically amplified photoresist compositions for thick plating films are disclosed (Patent Documents 2 to 6).
JP 2002-258479 A JP 2001-281862 A JP 2004-309775 A JP 2004-309776 A JP 2004-309777 A JP 2004-309778 A

  In order to solve the problems as described above, in the present invention, (1) no cracks due to thermal shock occur even when exposed to a low temperature of 0 ° C. or less, and (2) a thick film of 5 μm or more. A chemically amplified positive photoresist composition that satisfies the following conditions: (3) high sensitivity, (4) easily removable with a common solvent, and this photoresist composition An object is a method for forming a photoresist pattern using.

  A photoresist composition provided by the present invention comprises (A) a photoacid generator, (B) a resin component, and (C) an organic solvent, and a chemically amplified positive photoresist composition for low-temperature dry etching. It is a thing.

  The present invention provides the component (B) as at least one selected from a novolak resin, a polyhydroxystyrene resin, and an acrylic resin whose solubility in alkali is increased by the action of an acid, and an alkali-soluble novolak resin, There is also provided a chemically amplified positive photoresist composition for low-temperature dry etching, characterized in that it is at least one mixed resin selected from a polyhydroxystyrene resin and an acrylic resin.

  In the present invention, the component (B) is selected from at least one selected from alkali-soluble novolak resins and polyhydroxystyrene resins, and acrylic resins whose solubility in alkali is increased by the action of acid. There is also provided a chemically amplified positive photoresist composition for low-temperature dry etching, which is at least one kind of mixed resin.

  Such a chemically amplified positive photoresist composition for low-temperature dry etching provided by the present invention solves the above-described problems.

  According to the present invention, (1) cracks due to thermal shock do not occur even when exposed to a low temperature of 0 ° C. or lower, (2) it is possible to form a thick film of 5 μm or more, (3 Chemically amplified positive photoresist composition for low-temperature dry etching that satisfies the following conditions :) high sensitivity; and (4) that it can be easily removed with a general solvent, as well as this chemically amplified photoresist for low-temperature dry etching. A method of forming a photoresist pattern using the composition is provided.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this does not limit this invention at all.

[(A) Photoacid generator]
The photoacid generator (A) used in the chemically amplified positive photoresist composition for low-temperature dry etching according to the present invention is a substance that generates an acid directly or indirectly by irradiation with light (including radiation).

As a first embodiment of such a photoacid generator, 2,4-bis (trichloromethyl) -6-piperonyl-1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [ 2- (2-furyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (5-methyl-2-furyl) ethenyl] -s-triazine, 2,4-bis (Trichloromethyl) -6- [2- (5-ethyl-2-furyl) ethenyl] -s-triazine, 2,
4-bis (trichloromethyl) -6- [2- (5-propyl-2-furyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3,5-dimethoxy) Phenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3,5-diethoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl)- 6- [2- (3,5-dipropoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3-methoxy-5-ethoxyphenyl) ethenyl] -s -Triazine, 2,4-bis (trichloromethyl) -6- [2- (3-methoxy-5-propoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- [2- (3,4-methyl Rangeoxyphenyl) ethenyl] -s-triazine, 2,4-bis (trichloromethyl) -6- (3,4-methylenedioxyphenyl) -s-triazine, 2,4-bis-trichloromethyl-6- ( 3-bromo-4-methoxy) phenyl-s-triazine, 2,4-bis-trichloromethyl-6- (2-bromo-4-methoxy) phenyl-s-triazine, 2,4-bis-trichloromethyl-6 -(2-bromo-4-methoxy) styrylphenyl-s-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4-methoxy) styrylphenyl-s-triazine, 2- (4-methoxy Phenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxynaphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (5-methyl- 2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,5-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,4-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (3,4- Methylenedioxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, tris (1,3-dibromopropyl) -1,3,5-triazine, tris (2,3-dibromopropyl) ) Halogen such as 1,3,5-triazine Yes triazine compounds, and tris (2,3-dibromopropyl) isocyanurate - halogen-containing triazine compounds represented by the following general formula, such bets (a1) can be mentioned.

上記一般式（ａ１）中、Ｒ^１ａ、Ｒ^２ａ、およびＲ^３ａは、それぞれ独立なハロゲン化アルキル基である。

In the general formula (a1), R ^1a , R ^2a , and R ^3a are each independently an halogenated alkyl group.

  In addition, as a second embodiment of the photoacid generator, α- (p-toluenesulfonyloxyimino) -phenylacetonitrile, α- (benzenesulfonyloxyimino) -2,4-dichlorophenylacetonitrile, α- (benzenesulfonyloxy) Contains imino) -2,6-dichlorophenylacetonitrile, α- (2-chlorobenzenesulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, and oxime sulfonate groups And a compound represented by the following general formula (a2).

上記一般式（ａ２）中、Ｒ^４ａは、一価、二価、もしくは三価の有機基であり、また、Ｒ^５ａは、置換、未置換の飽和炭化水素基、不飽和炭化水素基または芳香族性化合物基であり、ｎは繰り返し単位である。

In the above general formula (a2), R ^4a is a monovalent, divalent or trivalent organic group, and R ^5a is a substituted, unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic group. A compound group, and n is a repeating unit.

In the general formula (a2), the aromatic compound group refers to a group of a compound exhibiting physical and chemical properties peculiar to the aromatic compound, for example, an aromatic hydrocarbon group such as a phenyl group or a naphthyl group, , Heterocyclic groups such as a furyl group and a thienyl group. These may have one or more suitable substituents on the ring, for example, a halogen atom, an alkyl group, an alkoxy group, a nitro group and the like. R ^5a is particularly preferably an alkyl group having 1 to 6 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. Particularly preferred are compounds wherein R ^4a is an aromatic compound group and R ^5a is a lower alkyl group.

As the photoacid generator represented by the general formula (a2), when n = 1, R ^4a is any one of a phenyl group, a methylphenyl group, and a methoxyphenyl group, and R ^5a is a methyl group, Specifically, α- (methylsulfonyloxyimino) -1-phenylacetonitrile, α- (methylsulfonyloxyimino) -1- (p-methylphenyl) acetonitrile, α- (methylsulfonyloxyimino) -1- (p -Methoxyphenyl) acetonitrile, [2- (propylsulfonyloxyimino) -2,3-dihydroxythiophene-3-ylidene] (o-tolyl) acetonitrile, and the like. When n = 2, the acid generator represented by the above general formula includes specifically an acid generator represented by the following chemical formula.

さらに、光酸発生剤の第三の態様としては、カチオン部にナフタレン環を有するオニウム塩を用いることができる。この「ナフタレン環を有する」とは、ナフタレンに由来する構造を有することを意味し、少なくとも２つの環の構造と、それらの芳香族性が維持されていることを意味する。このナフタレン環は炭素原子数１〜６の直鎖もしくは分岐鎖状のアルキル基、水酸基、炭素数１〜６の直鎖もしくは分岐鎖状のアルコキシ基等の置換基を有しいてもよい。ナフタレン環に由来する構造は、１価基（遊離原子価が１つ）であっても、２価基（遊離原子価が２つ）以上であってもよいが、１価基であることが望ましい（ただし、このとき、上記置換基と結合する部分を除いて遊離原子価を数えるものとする）。ナフタレン環の数は１〜３が好ましい。

Furthermore, as a third embodiment of the photoacid generator, an onium salt having a naphthalene ring in the cation portion can be used. This “having a naphthalene ring” means having a structure derived from naphthalene, and means that at least two ring structures and their aromaticity are maintained. The naphthalene ring may have a substituent such as a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. The structure derived from the naphthalene ring may be a monovalent group (one free valence) or a divalent group (two free valences) or more, but may be a monovalent group. Desirable (however, at this time, the free valence is counted excluding the portion bonded to the substituent). The number of naphthalene rings is preferably 1 to 3.

  As a cation part of the onium salt having a naphthalene ring in such a cation part, a structure represented by the following general formula (a3) is preferable.

上記一般式（ａ３）中、Ｒ^６ａ、Ｒ^７ａ、Ｒ^８ａのうち少なくとも１つは下記一般式（ａ４）で示される基であり、残りは炭素数１〜６の直鎖もしくは分岐鎖状のアルキル基、置換基を有していてもよいフェニル基、水酸基、または炭素数１〜６の直鎖もしくは分岐鎖状のアルコキシ基である。あるいは、Ｒ^６ａ、Ｒ^７ａ、Ｒ^８ａのうちの一つが下記一般式（ａ４）で示される基であり、残りの２つは、それぞれ独立して、炭素数１〜６の直鎖もしくは分岐鎖状アルキレン基であり、これらの末端が結合して環状になっていてもよい。

In the general formula (a3), at least one of R ^6a , R ^7a , and R ^8a is a group represented by the following general formula (a4), and the remainder is a linear or branched chain having 1 to 6 carbon atoms. An alkyl group, an optionally substituted phenyl group, a hydroxyl group, or a linear or branched alkoxy group having 1 to 6 carbon atoms. Alternatively, one of R ^6a , R ^7a and R ^8a is a group represented by the following general formula (a4), and the remaining two are each independently a straight chain or branched chain having 1 to 6 carbon atoms. An alkylene group, and these ends may be bonded to form a ring.

上記一般式（ａ４）中、Ｒ^９ａ、Ｒ^１０ａは、それぞれ独立して、水酸基、炭素数１〜６の直鎖もしくは分岐鎖状のアルコキシ基、または炭素数１〜６の直鎖もしくは分岐鎖状のアルキル基であり、Ｒ^１１ａは単結合または置換基を有していてもよい炭素数１〜６の直鎖もしくは分岐鎖状のアルキレン基であり、ｐ及びｑはそれぞれ独立して０または１〜２の整数であり、ｐ＋ｑは３以下である。ただし、Ｒ^１０ａが複数存在する場合、それらは相互に同じであっても異なっていてもよい。また、Ｒ^９ａが複数存在する場合、それらは相互に同じであっても異なっていてもよい。

In the general formula (a4), R ^9a and R ^10a are each independently a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, or a linear or branched chain having 1 to 6 carbon atoms. R ^11a is a linear or branched alkylene group having 1 to 6 carbon atoms which may have a single bond or a substituent, and p and q are each independently 0 or It is an integer of 1-2, and p + q is 3 or less. However, when two or more R ^<10a> exists, they may be mutually the same or different. When a plurality of R ^9a are present, they may be the same as or different from each other.

Of the above R ^6a , R ^7a , and R ^8a , the number of groups represented by the general formula (a4) is preferably one from the viewpoint of the stability of the compound, and the remainder is 1 to 6 carbon atoms. A linear or branched alkyl group or a phenyl group which may have a substituent, and these ends may be bonded to form a ring. In this case, the two alkylene groups constitute a 3- to 9-membered ring including a sulfur atom. The number of atoms (including sulfur atoms) constituting the ring is preferably 5-6
It is.

Examples of the substituent that the alkylene group may have include an oxygen atom (in this case, a carbonyl group is formed together with a carbon atom constituting the alkylene group), a hydroxyl group, and the like.
In addition, examples of the substituent that the phenyl group may have include a hydroxyl group, a linear or branched alkoxy group having 1 to 6 carbon atoms, or a linear or branched chain group having 1 to 6 carbon atoms. An alkyl group etc. are mentioned.

  Suitable examples of the cation moiety include those represented by the following chemical formulas (a5) and (a6), and the structure represented by the chemical formula (a6) is particularly preferable.

このようなカチオン部としては、ヨ−ドニウム塩であってもスルホニウム塩であってもよいが、酸発生効率等の点からスルホニウム塩が望ましい。

Such a cation moiety may be an iodonium salt or a sulfonium salt, but a sulfonium salt is desirable from the viewpoint of acid generation efficiency and the like.

Therefore, an anion capable of forming a sulfonium salt is desirable as a suitable anion part for an onium salt having a naphthalene ring in the cation part.
The anion moiety of such a photoacid generator is a fluoroalkyl sulfonate ion or an aryl sulfonate ion in which part or all of the hydrogen atoms are fluorinated.

  The alkyl group in the fluoroalkylsulfonic acid ion may be linear, branched or cyclic having 1 to 20 carbon atoms, and preferably has 1 to 10 carbon atoms from the bulk of the acid generated and its diffusion distance. . In particular, a branched or annular shape is preferable because of its short diffusion distance. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, and the like are preferable because they can be synthesized at a low cost.

  The aryl group in the aryl sulfonate ion is an aryl group having 6 to 20 carbon atoms, and examples thereof include an alkyl group, a phenyl group which may or may not be substituted with a halogen atom, and a naphthyl group. An aryl group having 6 to 10 carbon atoms is preferable because it can be synthesized. Specific examples include a phenyl group, a toluenesulfonyl group, an ethylphenyl group, a naphthyl group, and a methylnaphthyl group.

  In the fluoroalkyl sulfonate ion or aryl sulfonate ion, the fluorination rate when part or all of the hydrogen atoms are fluorinated is preferably 10 to 100%, more preferably 50 to 100%, In particular, those in which all hydrogen atoms are substituted with fluorine atoms are preferred because the strength of the acid is increased. Specific examples thereof include trifluoromethane sulfonate, perfluorobutane sulfonate, perfluorooctane sulfonate, and perfluorobenzene sulfonate.

  Especially, what is shown by the following general formula (a7) as a preferable anion part is mentioned.

上記一般式（ａ７）において、Ｒ^１２ａは、下記一般式（ａ８）、（ａ９）で示す構造や、化学式（ａ１０）で示す構造が挙げられる。

In the general formula (a7), examples of R ^12a include structures represented by the following general formulas (a8) and (a9) and structures represented by the chemical formula (a10).

上記一般式（ａ８）中、ｌは１〜４の整数であり、一般式（ａ９）中、Ｒ^１３ａは水素原子、水酸基、炭素原子数１〜６の直鎖もしくは分岐鎖状のアルキル基、または炭素原子数１〜６の直鎖もしくは分岐鎖状のアルコキシ基を示し、ｍは１〜３の整数である。中でも、安全性の観点からトリフルオロメタンスルホナート、パーフルオロブタンスルホナー
トが好ましい。

In the general formula (a8), l is an integer of 1 to 4, and in the general formula (a9), R ^13a is a hydrogen atom, a hydroxyl group, a linear or branched alkyl group having 1 to 6 carbon atoms, Or a C1-C6 linear or branched alkoxy group is shown, m is an integer of 1-3. Of these, trifluoromethanesulfonate and perfluorobutanesulfonate are preferable from the viewpoint of safety.

  Moreover, as an anion part, what contains the nitrogen represented by the following chemical formula (a11) and (a12) can also be used.

上記式（ａ１１）、（ａ１２）中、Ｘ^ａは、少なくとも１つの水素原子がフッ素原子で置換された直鎖状または分岐状のアルキレン基であり、該アルキレン基の炭素原子数は２〜６であり、好ましくは３〜５、最も好ましくは炭素原子数３である。また、Ｙ^ａ、Ｚ^ａは、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された直鎖状または分岐状のアルキル基であり、該アルキル基の炭素原子数は１〜１０であり、好ましくは１〜７、より好ましくは１〜３である。

The formula (a11), in (a12), X ^a represents a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, the number of carbon atoms of the alkylene group having 2 to 6 Preferably 3 to 5 and most preferably 3 carbon atoms. Y ^a and Z ^a are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms. , Preferably 1-7, more preferably 1-3.

X ^a number of carbon atoms of the alkylene group or Y ^a of ^the solubility of as the number of carbon atoms in the alkyl group of Z ^a small a resist solvent preferred for their good.
In addition, in the alkylene group of X ^a or the alkyl group of Y ^a and Z ^a , the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, which is preferable. The proportion of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. A perfluoroalkylene group or a perfluoroalkyl group.

  Preferable examples of the onium salt having a naphthalene ring at the cation moiety include compounds represented by the following chemical formulas (a13) and (a14).

さらに、光酸発生剤の別の態様としては、ビス（ｐ−トルエンスルホニル）ジアゾメタン、ビス（１，１−ジメチルエチルスルホニル）ジアゾメタン、ビス（シクロヘキシルスルホニル）ジアゾメタン、ビス（２，４−ジメチルフェニルスルホニル）ジアゾメタン等のビススルホニルジアゾメタン類；ｐ−トルエンスルホン酸２−ニトロベンジル、ｐ−トルエンスルホン酸２，６−ジニトロベンジル、ニトロベンジルトシラート、ジニトロベンジルトシラート、ニトロベンジルスルホナート、ニトロベンジルカルボナート、ジニトロベンジルカルボナート等のニトロベンジル誘導体；ピロガロールトリメシラート、ピロガロ−ルトリトシラ−ト、ベンジルトシラート、ベンジルスルホナート、Ｎ−メチルスルホニルオキシスクシンイミド、Ｎ−トリクロロメチルスルホニルオキシスクシンイミド、Ｎ−フェニルスルホニルオキシマレイミド、Ｎ−メチルスルホニルオキシフタルイミド等のスルホン酸エステル；Ｎ−ヒドロキシフタルイミド、Ｎ−ヒドロキシナフタルイミド等のトリフルオロメタンスルホン酸エステル類；ジフェニルヨードニウムヘキサフルオロホスファート、（４−メトキシフェニル）フェニルヨードニウムトリフルオロメタンスルホナート、ビス（ｐ−ｔｅｒｔ−ブチルフェニル）ヨードニウムトリフルオロメタンスルホナート、トリフェニルスルホニウムヘキサフルオロホスファート、（４−メトキシフェニル）ジフェニルスルホニウムトリフルオロメタンスルホナート、（ｐ−ｔｅｒｔ−ブチルフェニル）ジフェニルスルホニウムトリフルオロメタンスルホナート等のオニウム塩；ベンゾイントシラート、α−メチルベンゾイントシラート等のベンゾイントシレート類；その他のジフェニルヨ−ドニウム塩、トリフェニルスルホニウム塩、フェニルジアゾニウム塩、ベンジルカルボナ−ト等が挙げられる。

Further, as another embodiment of the photoacid generator, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) ) Bissulfonyldiazomethanes such as diazomethane; 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, nitrobenzyl tosylate, dinitrobenzyl tosylate, nitrobenzyl sulfonate, nitrobenzyl carbonate Nitrobenzyl derivatives such as dinitrobenzyl carbonate; pyrogallol trimesylate, pyrogallol tritosylate, benzyl tosylate, benzyl sulfonate, N-methylsulfonyloxysuccinimide, N Sulfonic acid esters such as trichloromethylsulfonyloxysuccinimide, N-phenylsulfonyloxymaleimide and N-methylsulfonyloxyphthalimide; trifluoromethanesulfonic acid esters such as N-hydroxyphthalimide and N-hydroxynaphthalimide; diphenyliodonium hexafluorophosphate (4-methoxyphenyl) phenyliodonium trifluoromethanesulfonate, bis (p-tert-butylphenyl) iodonium trifluoromethanesulfonate, triphenylsulfonium hexafluorophosphate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, (P-tert-butylphenyl) diphenylsulfonium trifluoromethanesulfo Onium salts over preparative like; benzoin tosylate, alpha-benzoin tosylate such as methyl benzoin tosylate; Other Jifeniruyo - Doniumu salts, triphenylsulfonium salts, phenyldiazonium salts, benzylcarboxy na - include bets and the like.

As the photoacid generator for the component (A), a compound of the general formula (a2) is preferably used. A preferable value of n is 2, and a preferable R ^4a has a divalent carbon number of 1. A substituted or unsubstituted alkylene group of ˜8, or a substituted or unsubstituted aromatic group, and preferred R ^5a is a substituted or unsubstituted alkyl group of 1 to 8 carbon atoms, or a substituted or unsubstituted group Although it is an aryl group, it is not limited to these.

The component (A) as described above can be used alone or in combination of two or more.
Moreover, the compounding quantity of (A) component shall be 0.1-20 mass parts with respect to 100 mass parts of total mass of the (B) component mentioned later, Preferably it is 0.2-10 mass parts. When the blending amount of the component (A) is 0.1 parts by mass or more, sufficient sensitivity can be obtained, and by 20 parts by mass or less, the solubility in a solvent is improved and a uniform solution is obtained. And storage stability tends to be improved.
[(B) Resin component]
The component (B) used in the chemically amplified positive photoresist composition for low temperature dry etching according to the present invention is at least one of a novolak resin (B1), a polyhydroxystyrene resin (B2), and an acrylic resin (B3). Or a mixed resin or copolymer.

  Such component (B) contains at least one selected from alkali-soluble novolak resin (B1-1), polyhydroxystyrene resin (B2-1), and acrylic resin (B3-1), and the action of acid. And a mixed resin with at least one selected from the group consisting of novolak resin (B1-2), polyhydroxystyrene resin (B2-2), and acrylic resin (B3-2) whose solubility in alkali increases. preferable.

[(B1-1) alkali-soluble novolak resin]
The alkali-soluble novolak resin (B1-1) preferably has a polystyrene-reduced mass average molecular weight (hereinafter referred to as mass average molecular weight) of 1,000 to 50,000.

  The novolak resin can be obtained, for example, by addition condensation of an aromatic compound having a phenolic hydroxyl group (hereinafter simply referred to as “phenols”) and an aldehyde under an acid catalyst. Examples of phenols used in this case include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p -Butylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3, 4,5-trimethylphenol, p-phenylphenol, resorcinol, hydroquinone, hydroquinone monomethyl ether, pyrogallol, phlorogricinol, hydroxydiphenyl, bisphenol A, gallic acid, gallic acid ester, α-naphthol, β-naphthol, etc. The

  Examples of aldehydes include formaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, and acetaldehyde. The catalyst for the addition condensation reaction is not particularly limited. For example, hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid and the like are used as the acid catalyst.

  In the present invention, the flexibility of the resin can be further improved by using o-cresol, substituting the hydrogen atom of the hydroxyl group in the resin with another substituent, or using bulky aldehydes. Is possible.

[(B2-1) Alkali-soluble polyhydroxystyrene resin]
The alkali-soluble polyhydroxystyrene resin (B2-1) preferably has a mass average molecular weight of 1,000 to 50,000.

  Examples of the hydroxystyrene-based compound constituting such a polyhydroxystyrene resin include p-hydroxystyrene, α-methylhydroxystyrene, α-ethylhydroxystyrene, and the like. Further, the polyhydroxystyrene resin is preferably a copolymer with a styrene resin. Examples of the styrene compound constituting the styrene resin include styrene, chlorostyrene, chloromethylstyrene, vinyltoluene, α-methyl. Examples include styrene.

[(B3-1) Alkali-soluble acrylic resin]
The alkali-soluble acrylic resin (B3-1) preferably has a mass average molecular weight of 50,000 to 800,000.

  Such an acrylic resin preferably contains a monomer derived from a polymerizable compound having an ether bond and a monomer derived from a polymerizable compound having a carboxyl group.

  Examples of the polymerizable compound having an ether bond include 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxypolyethylene glycol ( Examples include (meth) acrylic acid derivatives having an ether bond and an ester bond such as (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and preferably 2-methoxyethyl acrylate. And methoxytriethylene glycol acrylate. These compounds can be used alone or in combination of two or more.

  Examples of the polymerizable compound having a carboxyl group include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, 2-methacryloyloxyethyl succinic acid, and 2-methacryloyloxy. Examples thereof include compounds having a carboxyl group and an ester bond such as ethylmaleic acid, 2-methacryloyloxyethylphthalic acid and 2-methacryloyloxyethylhexahydrophthalic acid, and acrylic acid and methacrylic acid are preferred. These compounds can be used alone or in combination of two or more.

[(B1-2) Novolak resin whose solubility in alkali increases by the action of acid]
The novolak resin (B1-2) whose solubility in alkali is increased by the action of the acid is preferably 1000 to 50000 in mass average molecular weight.

  As the novolak resin (B1-2) whose solubility in alkali increases, a resin represented by the following general formula (b1) can be used.

上記一般式（ｂ１）中、Ｒ^１ｂは、酸解離性溶解抑制基であり、Ｒ^２ｂおよびＲ^３ｂは、それぞれ独立に水素原子もしくは炭素原子数１〜６のアルキル基であり、ｎは繰り返し単位を意味する。

In the general formula (b1), R ^1b is an acid dissociable, dissolution inhibiting group, R ^2b and R ^3b are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and n is a repeating unit. Means.

Furthermore, as the acid dissociable, dissolution inhibiting group represented by R ^1b , a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms represented by the following general formula (b2) or (b3): A tetrahydropyranyl group, a tetrafuranyl group, or a trialkylsilyl group is preferred.

上記一般式（ｂ２）および（ｂ３）中、Ｒ^４ｂ、およびＲ^５ｂは、それぞれ独立して水素原子又は炭素原子数１〜６の直鎖状又は分岐状のアルキル基であり、Ｒ^６ｂは炭素原子数１〜１０の直鎖状、分岐状又は環状のアルキル基であり、Ｒ^７ｂは炭素原子数１〜６の直鎖状、分岐状又は環状のアルキル基であり、ｏは０又は１である。

In the general formulas (b2) and (b3), R ^4b and R ^5b are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ^6b is carbon. A linear, branched or cyclic alkyl group having 1 to 10 atoms, R ^7b is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, and o is 0 or 1 is there.

  In addition, as a linear or branched alkyl group having 1 to 6 carbon atoms, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, iso-butyl group, tert-butyl group, pentyl group , Isopentyl group, neopentyl group and the like, and cyclic alkyl group include cyclopentyl group, cyclohexyl group and the like.

  Here, as the acid dissociable, dissolution inhibiting group represented by the general formula (b2), specifically, methoxyethyl group, ethoxyethyl group, n-propoxyethyl group, iso-propoxyethyl group, n-butoxyethyl group , Iso-butoxyethyl group, tert-butoxyethyl group, cyclohexyloxyethyl group, methoxypropyl group, ethoxypropyl group, 1-methoxy-1-methyl-ethyl group, 1-ethoxy-1-methylethyl group, etc. Examples of the acid dissociable, dissolution inhibiting group of the above formula (b3) include a tert-butoxycarbonyl group and a tert-butoxycarbonylmethyl group. Examples of the trialkylsilyl group include those having 1 to 6 carbon atoms in each alkyl group such as a trimethylsilyl group and a tri-tert-butyldimethylsilyl group.

[(B2-2) Polyhydroxystyrene resin whose solubility in alkali is increased by the action of acid]
The polyhydroxystyrene resin (B2-2) whose solubility in alkali is increased by the action of the acid is preferably 1,000 to 50,000.

  As such a polyhydroxystyrene resin (B2-2), a resin represented by the following general formula (b4) can be used.

上記一般式（ｂ４）中、Ｒ^８ｂは、水素原子もしくは炭素数１〜６のアルキル基であり、Ｒ^９ｂは、酸解離性溶解抑制基であり、ｎは繰り返し単位を意味する。

In the general formula (b4), R ^8b is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R ^9b is an acid dissociable, dissolution inhibiting group, and n is a repeating unit.

  In addition, as a linear or branched alkyl group having 1 to 6 carbon atoms, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, iso-butyl group, tert-butyl group, pentyl group , Isopentyl group, neopentyl group and the like, and cyclic alkyl group include cyclopentyl group, cyclohexyl group and the like.

As the acid dissociable, dissolution inhibiting group represented by R ^9b , the same acid dissociable, dissolution inhibiting groups as exemplified in the general formulas (b2) and (b3) can be used.
Furthermore, the polyhydroxystyrene resin (B2-2) whose solubility in alkali is increased by the action of the acid contains other polymerizable compound as a structural unit for the purpose of appropriately controlling physical and chemical properties. Can do. Examples of such polymerizable compounds include known radical polymerizable compounds and anionic polymerizable compounds. For example, monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl Methacrylic acid derivatives having a carboxyl group and an ester bond such as phthalic acid and 2-methacryloyloxyethylhexahydrophthalic acid; (meth) acrylic acid such as methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth) acrylate Alkyl esters; (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; phenyl (meth) acrylate, benzyl ( And (meth) acrylic acid aryl esters such as acrylate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α- Vinyl group-containing aromatic compounds such as methylhydroxystyrene and α-ethylhydroxystyrene; Vinyl group-containing aliphatic compounds such as vinyl acetate; Conjugated diolefins such as butadiene and isoprene; Nitrile groups such as acrylonitrile and methacrylonitrile -Containing polymerizable compounds; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; amide bond-containing polymerizable compounds such as acrylamide and methacrylamide.

[(B3-2) Acrylic resin whose solubility in alkali is increased by the action of acid]
As an acrylic resin (B3-2) whose solubility with respect to an alkali increases by the effect | action of the said acid, it is preferable that a mass mean molecular weight is 10000-500000.

  As the acrylic resin (B3-2), resins represented by the following general formulas (b5) to (b7) can be used.

上記一般式（ｂ５）〜（ｂ７）中、Ｒ^１０ｂ〜Ｒ^１７ｂは、それぞれ独立して水素原子又は炭素原子数１〜６の直鎖状又は分岐状のアルキル基、フッ素原子又は炭素原子数１〜６の直鎖状又は分岐状のフッ素化アルキル基であり（ただし、Ｒ^１１ｂが水素原子であることはない）、Ｘはそれが結合している炭素原子と共に炭素原子数５〜２０の炭化水素環を形成し、Ｙは置換基を有していてもよい脂肪族環式基又はアルキル基であり、ｎは繰り返し単位を意味し、ｐは０〜４であり、ｑは０又は１である。

In the general formulas (b5) to (b7), R ^{10b to} R ^17b are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, a fluorine atom, or 1 carbon atom. A linear or branched fluorinated alkyl group of ˜6 (provided that R ^11b is not a hydrogen atom), and X is a carbon atom having 5 to 20 carbon atoms together with the carbon atom to which it is bonded. A hydrogen ring is formed, Y is an optionally substituted aliphatic cyclic group or an alkyl group, n is a repeating unit, p is 0 to 4, and q is 0 or 1. is there.

  In addition, as a linear or branched alkyl group having 1 to 6 carbon atoms, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, iso-butyl group, tert-butyl group, pentyl group , Isopentyl group, neopentyl group and the like, and cyclic alkyl group include cyclopentyl group, cyclohexyl group and the like. The fluorinated alkyl group is one in which part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms.

R ^11b is preferably a linear or branched alkyl group having 2 to 4 carbon atoms from the viewpoint of high contrast, good resolution, depth of focus, etc., and the R ^13b , R ^14b R ^16b and R ^17b are preferably a hydrogen atom or a methyl group.

^Xb together with the carbon atom to which it is bonded forms an aliphatic cyclic group having 5 to 20 carbon atoms. Specific examples of such an aliphatic cyclic group include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Specifically, one or more hydrogen atoms were removed from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Groups. In particular, a group obtained by removing one or more hydrogen atoms from cyclohexane or adamantane (which may further have a substituent) is preferable.

Furthermore, when the aliphatic cyclic group of ^Xb has a substituent on the ring skeleton, examples of the substituent include polar groups such as a hydroxyl group, a carboxy group, a cyano group, and an oxygen atom (═O). And a linear or branched lower alkyl group having 1 to 4 carbon atoms. As the polar group, an oxygen atom (═O) is particularly preferable.

  Y is an aliphatic cyclic group or an alkyl group, and examples thereof include a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Specifically, one or more hydrogen atoms were removed from monocycloalkanes such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Groups and the like. In particular, a group in which one or more hydrogen atoms are removed from adamantane (which may further have a substituent) is preferable.

Furthermore, the aliphatic cyclic group for the Y ^b is a case having a substituent on the ring skeleton, examples of the substituent, a hydroxyl group, a carboxyl group, a cyano group, a polar group such as an oxygen atom (= O) And a linear or branched lower alkyl group having 1 to 4 carbon atoms. As the polar group, an oxygen atom (═O) is particularly preferable.

Also, if Y ^b is an alkyl group, having 1 to 20 carbon atoms, it is preferred that preferably a linear or branched alkyl group having 6 to 15. Such an alkyl group is particularly preferably an alkoxyalkyl group. Examples of such an alkoxyalkyl group include 1-methoxyethyl group, 1-ethoxyethyl group, 1-n-propoxyethyl group, 1-iso- Propoxyethyl group, 1-n-butoxyethyl group, 1-iso-butoxyethyl group, 1-tert-butoxyethyl group, 1-methoxypropyl group, 1-ethoxypropyl group, 1-methoxy-1-methyl-ethyl group And 1-ethoxy-1-methylethyl group.

  Preferable specific examples of the acrylic resin represented by the general formula (b5) include those represented by the following general formulas (b5-1) to (b5-3).

上記一般式（ｂ５−１）〜（ｂ５−３）中のＲ^１８ｂは水素原子又はメチル基であり、ｎは繰り返し単位である。

R ^18b in the general formulas (b5-1) to (b5-3) is a hydrogen atom or a methyl group, and n is a repeating unit.

  Preferable specific examples of the acrylic resin represented by the general formula (b6) include those represented by the following general formulas (b6-1) to (b6-28).

上記一般式（ｂ７）で表わされるアクリル樹脂の好ましい具体例としては、下記一般式（ｂ７−１）〜（ｂ７−２２）で表されるのものを挙げることができる。

Preferable specific examples of the acrylic resin represented by the general formula (b7) include those represented by the following general formulas (b7-1) to (b7-22).

さらに、酸の作用によりアルカリに対する溶解性が増大するアクリル樹脂（Ｂ３−２）は、前記一般式（ｂ５）〜（ｂ７）の構成単位に対して、さらにエーテル結合を有する重合性化合物から誘導された構成単位を含む共重合体からなる樹脂であることが好ましい。

Further, the acrylic resin (B3-2) whose solubility in alkali is increased by the action of an acid is derived from a polymerizable compound having an ether bond with respect to the structural units of the general formulas (b5) to (b7). It is preferably a resin made of a copolymer containing structural units.

Such a structural unit is a structural unit derived from a polymerizable compound having an ether bond. Examples of the polymerizable compound having an ether bond include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol ( Exemplified radical polymerizable compounds such as (meth) acrylic acid derivatives having ether bonds and ester bonds such as (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate Preferably, it is 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate. These compounds can be used alone or in combination of two or more.

  Furthermore, the acrylic resin (B3-2) whose solubility in alkali is increased by the action of the acid can contain other polymerizable compounds as constituent units for the purpose of appropriately controlling physical and chemical properties. . Examples of such polymerizable compounds include known radical polymerizable compounds and anionic polymerizable compounds. For example, monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid; 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyethyl maleic acid, 2-methacryloyloxyethyl Methacrylic acid derivatives having a carboxyl group and an ester bond such as phthalic acid and 2-methacryloyloxyethylhexahydrophthalic acid; (meth) acrylic acid such as methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth) acrylate Alkyl esters; (meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; phenyl (meth) acrylate, benzyl ( And (meth) acrylic acid aryl esters such as acrylate; dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; styrene, α-methylstyrene, chlorostyrene, chloromethylstyrene, vinyltoluene, hydroxystyrene, α- Vinyl group-containing aromatic compounds such as methylhydroxystyrene and α-ethylhydroxystyrene; Vinyl group-containing aliphatic compounds such as vinyl acetate; Conjugated diolefins such as butadiene and isoprene; Nitrile groups such as acrylonitrile and methacrylonitrile -Containing polymerizable compounds; chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; amide bond-containing polymerizable compounds such as acrylamide and methacrylamide.

  Among the components (B), the alkali-soluble resin components represented by (B1-1), (B2-1), and (B3-1) include (B1-2), (B2-2), and (B3 -2) It is preferable to make it the mixed resin which combined the resin component which alkali solubility increases by the effect | action of the acid represented.

  More preferably, the component (B) is represented by (B2-2) and (B3-2) in the alkali-soluble resin component represented by (B1-1), (B2-1), and (B3-1). It is preferable to use a mixed resin in which resin components whose alkali solubility is increased by the action of the acid to be combined are combined.

  In particular, the alkali-soluble resin component is alkali-soluble by the action of the alkali-soluble novolak resin and alkali-soluble polyhydroxystyrene resin represented by (B1-1) and (B2-1) and the acid represented by (B3-2). It is preferable to use a mixed resin in combination with an acrylic resin that increases the viscosity.

  Among the alkali-soluble novolak resins (B1-1), it is preferable to have a composition in which m-cresol and p-cresol are combined as phenols, and particularly, the mass ratio of m-cresol and p-cresol is 50:50 to 50-50. Alkali-soluble novolac resins combined at 70:30 are preferred.

  Among the alkali-soluble polyhydroxystyrene resins (B2-1), it is preferable to use a copolymer of styrene and hydroxystyrene. In particular, an alkali in which styrene and hydroxystyrene are combined at a mass ratio of 100: 0 to 75:25. A soluble polyhydroxystyrene resin is preferred.

  Among the acrylic resin (B3-2) whose alkali solubility is increased by the action of the acid, a structural unit represented by the general formula (7), a structural unit derived from a polymerizable compound having an ether bond, It is preferably a copolymer having acrylic acid units and structural units composed of (meth) acrylic acid alkyl esters.

  Such a copolymer is preferably a copolymer represented by the following general formula (b8).

上記一般式（ｂ８）中、Ｒ^２０ｂは、水素原子又はメチル基であり、Ｒ^２１ｂは、炭素原子数１〜６の直鎖状又は分岐状のアルキル基又はアルコキシアルキル基であり、Ｒ^２２ｂは、炭素原子数２〜４の直鎖状又は分岐状のアルキル基であり、Ｘ^ａは前述の定義と同様である。

In the general formula (b8), R ^20b is a hydrogen atom or a methyl group, R ^21b is a linear or branched alkyl group or alkoxyalkyl group having 1 to 6 carbon atoms, and R ^22b is a linear or branched alkyl group having 2 to 4 carbon atoms, is X ^a is the same as defined above.

  Furthermore, in the copolymer represented by the general formula (b8), s, t, and u are each in a mass ratio, s is 1 to 30% by mass, t is 20 to 70% by mass, u Is 20-70 mass%.

  Moreover, when it is set as the mixed resin which combined the said (B1-1), (B2-1), and (B3-2), (B1-1) is 30-60 mass% in (B) component, (B2 -1) is preferably 3 to 20% by mass, and (B3-2) is preferably 20 to 70% by mass.

  By using such a component (B), it is possible to ensure the resistance to the dry etching process even when the dry etching process is performed under a cryogenic condition of 0 ° C. to −100 ° C. Has an effect that cracks and the like do not occur even when cooled from room temperature to extremely low temperature.

  In addition, as for (B) component, it is preferable that the glass transition point of the whole resin component shall be 0 degrees C or less, and when using mixed resin or a copolymer, a glass transition point is converted into a theoretical glass transition point, and is calculated. . The theoretical glass transition point is obtained by adding the product obtained by multiplying the glass transition point of each resin or structural unit by the number of mass parts occupied by each resin or structural unit and dividing the result by 100.

[(C) Organic solvent]
(C) Organic solvents include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone; ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate Polyhydric alcohols such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or monophenyl ether of dipropylene glycol and dipropylene glycol monoacetate and derivatives thereof; cyclic ethers such as dioxane; Ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, Ethyl Rubin, ethyl ethoxy acetate, methyl methoxypropionate, ethyl ethoxypropionate, 2-hydroxypropionic acid, 2-
Esters such as ethyl hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate; toluene, Aromatic hydrocarbons such as xylene can be mentioned.
These may be used alone or in combination of two or more.

  The amount of these organic solvents used is such that the film thickness of the photoresist layer obtained by using the chemically amplified positive photoresist composition for low temperature dry etching according to the present invention (for example, by spin coating) is 5 μm or more. A range in which the solid content concentration is 30% by mass or more is preferable. Preferably, the film thickness of the photoresist layer obtained using the composition according to the present invention is in the range of 5 μm to 200 μm.

  In the chemically amplified positive photoresist composition for low-temperature dry etching of the present invention, a surfactant can be optionally blended depending on the purpose of improving the coating property, defoaming property, leveling property and the like. Examples of surfactants include BM-1000, BM-1100 (all trade names; manufactured by BM Chemie), MegaFuck F142D, MegaFuck F172, MegaFuck F173, MegaFuck F183 (all trade names; Dainippon INK CHEMICAL INDUSTRY CO., LTD.), FLORARD FC-135, FLORARD FC-170C, FLORARD FC-430, FLORARD FC-431 (all trade names; manufactured by Sumitomo 3M), Surflon S-112, Surflon S- 113, Surflon S-131, Surflon S-141, Surflon S-145 (all trade names; manufactured by Asahi Glass Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428 (any There are also commercially available fluorosurfactants such as Toray Silicone Co., Ltd. Not done.

[(D) polyvinyl resin]
The chemical amplification positive photoresist composition for low-temperature dry etching according to the present invention may further contain (D) a polyvinyl resin as necessary. Such a polyvinyl resin is poly (vinyl lower alkyl ether), and can be obtained by polymerizing a single or a mixture of two or more vinyl lower alkyl ethers represented by the following general formula (d1). Composed of coalescence.

上記一般式（ｄ１）において、Ｒ^１ｄは炭素原子数１〜６の直鎖状又は分岐状のアルキル基である。

In the above general formula (d1), R ^1d is a linear or branched alkyl group having 1 to 6 carbon atoms.

  Such a polyvinyl resin is a polymer obtained from a vinyl-based compound. Specific examples of such a polyvinyl resin include polyvinyl chloride, polystyrene, polyhydroxystyrene, polyvinyl acetate, polyvinyl benzoic acid, polyvinyl Examples include methyl ether, polyvinyl ethyl ether, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl phenol, and copolymers thereof. Among these, polyvinyl methyl ether is preferable in view of the low glass transition point.

  The mass average molecular weight of such a polyvinyl resin is preferably 10,000 to 200,000, more preferably 50,000 to 100,000. By blending such a polyvinyl resin, it is possible to impart resistance to the dry etching process even when the dry etching process is performed under extremely low temperature conditions of 0 ° C. to −100 ° C.

When mix | blending such a polyvinyl resin, it is preferable to set it as 5-95 mass parts with respect to 100 mass parts of said (B) component.
[(E) Acid diffusion controller]
The chemically amplified positive photoresist composition for low-temperature dry etching according to the present invention may further contain an acid diffusion controller as the component (E).

  As the acid diffusion controlling agent, a nitrogen-containing compound is preferable, and an organic carboxylic acid, or an oxo acid of phosphorus or a derivative thereof can be further contained as necessary.

[(E1) Nitrogen-containing compound]
Examples of the nitrogen-containing compound (e1) include trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tribenzylamine, diethanolamine, triethanolamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylether, 4 , 4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, prop Pionamide, benzamide, pyrrolidone, N-methylpyrrolidone, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, imidazole, benzimidazole 4-methylimidazole, 8-oxyquinoline, acridine, purine, pyrrolidine, piperidine, 2,4,6-tri (2-pyridyl) -S-triazine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethyl Examples include piperazine and 1,4-diazabicyclo [2.2.2] octane. Of these, alkanolamines such as triethanolamine are particularly preferred. These may be used alone or in combination of two or more.

  Such a nitrogen-containing compound is usually used in a range of 0 to 5% by mass, more preferably in a range of 0 to 3% by mass, when the above-described component (B) is 100% by mass.

[(E2) Organic carboxylic acid or phosphorus oxo acid or derivative thereof]
(E2) As the organic carboxylic acid, specifically, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are preferable, and salicylic acid is particularly preferable.

  Examples of phosphorus oxoacids or derivatives thereof include phosphoric acid, phosphoric acid di-n-butyl ester, phosphoric acid diphenyl ester, and the like, derivatives such as phosphonic acid, phosphonic acid dimethyl ester, phosphonic acid, etc. Phosphonic acids such as acid di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid dibenzyl ester and derivatives thereof, phosphinic acids such as phosphinic acid, phenylphosphinic acid and esters thereof Among these, phosphonic acid is particularly preferable. These may be used alone or in combination of two or more.

  These organic carboxylic acids or phosphorus oxo acids or derivatives thereof are usually used in the range of 0 to 5% by mass, more preferably 0 to 3% by mass, when the component (B) is 100% by mass. It is used in the range.

In order to form a salt and stabilize it, it is preferable to use an organic carboxylic acid, or an oxo acid of phosphorus or a derivative thereof in an amount equivalent to the above-mentioned nitrogen-containing compound.
The chemical amplification type positive photoresist composition for low-temperature dry etching according to the present invention may further contain an adhesion aid in order to improve the adhesion to the substrate. As the adhesion assistant used, a functional silane coupling agent is preferable. The above-mentioned functional silane coupling agent means a silane coupling agent having a reactive substituent such as a carboxyl group, a methacryloyl group, an isocyanate group, and an epoxy group, and specific examples include trimethoxysilyl benzoate. Examples include acids, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. it can. It is preferable that the compounding quantity is 20 mass parts or less with respect to 100 mass parts of (B) component.

  In addition, an acid, an acid anhydride, or a high-boiling solvent may be added to the chemically amplified positive photoresist composition for low-temperature dry etching according to the present invention in order to finely adjust the solubility in an alkali developer. it can. Examples of the acids and acid anhydrides mentioned above include monocarboxylic acids such as acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid, benzoic acid, cinnamic acid, and lactic acid, 2-hydroxy Hydroxy such as butyric acid, 3-hydroxybutyric acid, salicylic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, 4-hydroxycinnamic acid, 5-hydroxyisophthalic acid, syringic acid Monocarboxylic acids, as well as oxalic acid, succinic acid, glutaric acid, adipic acid, maleic acid, itaconic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,2-cyclohexanedicarboxylic acid, 1,2, 4-cyclohexanetricarboxylic acid, butanetetracarboxylic acid, trimellitic acid, pyromellitic acid, cyclope Polycarboxylic acid such as tantetracarboxylic acid, butanetetracarboxylic acid, 1,2,5,8-naphthalenetetracarboxylic acid, itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarbanilic anhydride, anhydrous Maleic acid, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hymic anhydride, 1,2,3,4-butanetetracarboxylic anhydride, cyclopentanetetracarboxylic dianhydride, phthalic anhydride, pyromellitic anhydride And acid anhydrides such as acid, trimellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitic anhydride, and glycerin tris anhydrous trimellitate. Examples of the high boiling point solvent described above include N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, Benzyl ethyl ether, dihexyl ether, acetonyl acetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, carbonic acid Mention may be made of ethylene, propylene carbonate, phenyl cellosolve acetate and the like. The amount of the compound used for finely adjusting the solubility in the alkali developer as described above can be adjusted according to the application and application method, and is particularly limited as long as the composition can be mixed uniformly. Although it is not a thing, it is 60 mass% or less with respect to the composition obtained, Preferably it is 40 mass% or less.

  Moreover, a filler, a coloring agent, a viscosity modifier, etc. can also be added to the chemically amplified positive photoresist composition for low temperature dry etching according to the present invention as long as the characteristics are not impaired.

Examples of the filler include silica, alumina, talc, bentonite, zirconium silicate, powdered glass and the like. Colorants include extender pigments such as alumina white, clay, barium carbonate, barium sulfate, zinc white, lead white, yellow lead, red lead, ultramarine, bitumen, titanium oxide, zinc chromate, bengara, carbon black, etc. Inorganic pigments, organic pigments such as brilliant carmine 6B, permanent red 6B, permanent red R, benzidine yellow, phthalocyanine blue, phthalocyanine green, basic dyes such as magenta and rhodamine, and direct scarlet, direct orange, etc. And direct dyes, and acid dyes such as roserine and metanyl yellow. Examples of the viscosity modifier include bentonite, silica gel, aluminum powder and the like. Preferably, the addition amount of these additives is 5% by mass or less based on the obtained composition.

[Preparation]
In the preparation of the chemically amplified positive photoresist composition for low temperature dry etching according to the present invention, when the filler and the pigment are not added, for example, the above components may be mixed and stirred by a usual method, In the case where a filler and a pigment are not added, they may be dispersed and mixed using a disperser such as a dissolver, a homogenizer, or a three-roll mill, if necessary. Further, after mixing, it may be further filtered using a mesh, a membrane filter or the like.

  The chemically amplified positive photoresist composition for low-temperature dry etching according to the present invention is suitable for forming a photoresist layer having a thickness of 5 to 1000 μm, more preferably 5 to 200 μm on a support, It can also be applied to processing under conditions.

[Photoresist pattern formation]
The above-described photoresist layer can be manufactured, for example, as follows.

  (1) Formation of a coating film: A solution of a chemically amplified positive photoresist composition for low-temperature dry etching prepared as described above is applied onto a support and a desired coating film is formed by removing the solvent by heating. To do. As a coating method on a to-be-processed support body, methods, such as a spin coat method, a slit coat method, a roll coat method, a screen printing method, an applicator method, are employable. The prebaking conditions for the coating film of the composition of the present invention vary depending on the type of each component in the composition, the blending ratio, the coating film thickness, etc., but are usually 70 to 150 ° C., preferably 80 to 140 ° C., 20 ~ About 60 minutes.

(2) Radiation irradiation: By selectively irradiating the photoresist layer obtained as described above with radiation (for example, ultraviolet rays or visible rays having a wavelength of 300 to 500 nm) through a mask having a predetermined pattern. , Expose. As these radiation sources, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like can be used. Here, the radiation means ultraviolet rays, visible rays, far ultraviolet rays, X-rays, electron beams, ion rays, and the like. The amount of radiation irradiation varies depending on the type of each component in the composition, the blending amount, the film thickness of the coating film, and the like, for example, when using an ultrahigh pressure mercury lamp, it is 100 to 10000 mJ / cm ² , more preferably 100 to 2000 mJ. / Cm ² .

  (3) Development: As a development method after radiation irradiation, for example, a predetermined alkaline aqueous solution is used as a developer, and unnecessary portions are dissolved and removed to obtain a predetermined resist pattern. As the developer, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethyl Ethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene, 1,5-diazabicyclo [4,3,0 An aqueous solution of an alkali such as -5-nonane can be used. In addition, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the alkaline aqueous solution may be used as a developer.

The development time varies depending on the type of each component of the composition, the blending ratio, and the dry film thickness of the composition, but it is usually 1 to 30 minutes. Any of these may be used. After the development, washing with running water is performed for 30 to 90 seconds and dried using an air gun, oven or the like.

  40 parts by mass represented by the following general formula (z1), 48 parts by mass of a novolak resin obtained by addition condensation of m-cresol and p-cresol in the presence of formaldehyde and an acid catalyst, and a copolymer of styrene / hydroxystyrene 12 parts by mass were mixed to obtain a resin component (B).

前記（Ｂ）樹脂成分１００質量部に対して、光酸発生剤である下記化学式（ｚ２）で表わされる化合物を１．０質量部、サリチル酸を０．１質量部、トリエタノールアミンを０．１質量部、それぞれ配合し、プロピレングリコールモノメチルエーテルアセタートに溶解して、固形分質量濃度を４０質量％とした低温ドライエッチング用化学増幅型ポジ型レジスト組成物を調整した。

With respect to 100 parts by mass of the resin component (B), 1.0 part by mass of a compound represented by the following chemical formula (z2), which is a photoacid generator, 0.1 part by mass of salicylic acid, 0.1% of triethanolamine A chemical amplification type positive resist composition for low-temperature dry etching with a solid content mass concentration of 40% by mass was prepared by mixing each part by mass and dissolving in propylene glycol monomethyl ether acetate.

次いで、シリコン基板上に、前記低温ドライエッチング用ポジ型ホトレジスト組成物を１０００ｒｐｍにて２５秒間塗布した後、１１０℃で６分間ホットプレート上でプレベークし、膜厚約２０μｍの塗膜を形成した。次に、パターンマスクを介して、超高圧水銀灯（ウシオ製ＵＳＨ−２５０Ｄ）を用いて、露光量１５００ｍＪ／ｃｍ^２で紫外線露光を行った。露光後、塗膜を現像液（商品名;Ｐ−７Ｇ、東京応化工業社製）で現像した。その後、流水洗浄し、窒素ブローしてパターン状硬化物を得た。

Next, the positive photoresist composition for low-temperature dry etching was applied on a silicon substrate at 1000 rpm for 25 seconds, and then pre-baked on a hot plate at 110 ° C. for 6 minutes to form a coating film having a thickness of about 20 μm. Next, ultraviolet exposure was performed at an exposure amount of 1500 mJ / cm ² using an ultrahigh pressure mercury lamp (USH-250D manufactured by USHIO) through a pattern mask. After the exposure, the coating film was developed with a developer (trade name; P-7G, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, it was washed with running water and blown with nitrogen to obtain a patterned cured product.

With the silicon substrate cooled to −20 ° C. and using a reactive gas composed of CF ₄ , SF ₆ , O ₂ and N _2, the patterned cured product produced in Preparation Example 1 described above as a mask, The aforementioned silicon substrate was etched and etched to a depth of 180 μm. At this time, the resist pattern was in a state where no cracks or the like were generated, and a 180 μm diameter hole-like structure was formed on the silicon substrate.

  As described above, according to the present invention, (1) cracks due to thermal shock do not occur even when exposed to a low temperature of 0 ° C. or lower, and (2) a thick film of 5 μm or more is formed. Chemically amplified positive photoresist composition for low-temperature dry etching that satisfies the following conditions: (3) high sensitivity, (4) easy peeling with common solvents, and the photoresist A photoresist pattern forming method using the composition is obtained.

Claims (11)

  A chemical amplification type positive photoresist composition for low temperature dry etching, comprising (A) a photoacid generator, (B) a resin component, and (C) an organic solvent.   The chemically amplified positive photoresist composition for low temperature dry etching according to claim 1, which is a chemically amplified positive photoresist composition subjected to a dry etching process performed at 0 ° C or lower.   3. The chemically amplified positive photoresist composition for low-temperature dry etching according to claim 1, wherein the chemically amplified positive photoresist composition is used for a process for forming a photoresist film having a thickness of 5 to 200 [mu] m.   The low-temperature dry etching chemistry according to any one of claims 1 to 3, wherein the component (B) is at least one selected from a novolac resin, a polyhydroxystyrene resin, and an acrylic resin. Amplified positive photoresist composition.   The component (B) is at least one selected from a novolak resin, a polyhydroxystyrene resin, and an acrylic resin whose solubility in alkali is increased by the action of an acid, and an alkali-soluble novolak resin, a polyhydroxystyrene resin, and The chemically amplified positive photoresist composition for low-temperature dry etching according to any one of claims 1 to 4, wherein the composition is at least one mixed resin selected from acrylic resins.   The component (B) is at least one selected from polyhydroxystyrene resins and acrylic resins whose solubility in alkali is increased by the action of an acid, and alkali-soluble novolak resins, polyhydroxystyrene resins, and acrylic resins. The chemically amplified positive photoresist composition for low-temperature dry etching according to any one of claims 1 to 5, wherein the resin composition is at least one mixed resin selected from the group consisting of:   The component (B) is an acrylic resin whose solubility in alkali is increased by the action of an acid, and at least one mixed resin selected from alkali-soluble novolak resins and polyhydroxystyrene resins. The chemically amplified positive photoresist composition for low-temperature dry etching according to any one of claims 1 to 6. 8. The low-temperature dry etching according to claim 1, wherein a glass transition point (T _g ) of at least one resin component selected from the component (B) is 0 ° C. or lower. Chemically amplified positive photoresist composition.   Furthermore, (D) Polyvinyl resin is included, The chemical amplification type positive photoresist composition for low-temperature dry etching as described in any one of Claims 1-8 characterized by the above-mentioned.   The chemical amplification type positive photoresist composition for low temperature dry etching according to any one of claims 1 to 9, further comprising (E) an acid diffusion controller.   A chemically amplified positive photoresist composition for low temperature dry etching according to any one of claims 1 to 10 is applied on a substrate to form a photoresist film having a thickness of 5 to 200 µm, and the resulting photoresist film A method for forming a photoresist pattern, which comprises irradiating with radiation through a predetermined pattern mask and developing.