JP4483405B2 - Novel polymer and radiation-sensitive resin composition - Google Patents

Description

  The present invention relates to a novel polymer and a radiation-sensitive resin composition, and more specifically, various kinds of radiation such as far ultraviolet rays such as F2 excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams. The present invention relates to a radiation-sensitive resin composition useful as a chemically amplified resist used for fine processing and a novel fluorine-containing vinyl ether polymer useful as a resin component of the radiation-sensitive resin composition.

In recent years, demands for higher density and higher integration of LSIs (highly integrated circuits) are increasing, and along with this, miniaturization of wiring patterns is also progressing rapidly.
As one of the means that can cope with such miniaturization of the wiring pattern, there is a method of shortening the radiation used in the lithography process. In recent years, g-line (wavelength 436 nm), i-line (wavelength 365 nm), etc. Instead of ultraviolet rays, far ultraviolet rays represented by KrF excimer laser (wavelength 248 nm) or ArF excimer laser (wavelength 193 nm), X-rays, electron beams, etc. are used, and F ₂ excimer laser (wavelength) 157 nm) is also being considered.
By the way, as a conventional resist resin component, an aromatic polymer such as a phenol novolac resin is generally used, and the aromatic polymer is strongly derived from an aromatic ring against radiation having a wavelength of 200 nm or less. Since there is absorption, high accuracy corresponding to high sensitivity, high resolution, and high aspect ratio cannot be obtained in a lithography process using an ArF excimer laser or F2 excimer laser. Accordingly, there is a demand for a resist resin component that has a dry etching resistance equivalent to or higher than that of an aromatic ring and is excellent in transparency to radiation having a wavelength of 200 nm or less.

One example is a siloxane-based polymer, and MIT RRKunz et al. Show that the siloxane-based polymer has excellent transparency at a wavelength of 200 nm or less, particularly at a wavelength of 157 nm, and this polymer uses a wavelength of 193 nm or less. It is reported that it is suitable for a resin component in a lithography process (for example, see Non-Patent Document 1). Siloxane polymers are also known to be excellent in dry etching resistance, and in particular, resists containing polyorganosilsesquioxane having a ladder structure have high plasma resistance.
On the other hand, some resist materials using siloxane polymers have already been reported. Namely, a radiation sensitive resin using a vinyl polymer having an acid dissociable group in a side chain in which an acid dissociable group such as a carboxylic acid ester group or a phenol ether group is bonded to a silicon atom via one or more carbon atoms. Composition (for example, see Patent Document 1), positive resist using a polymer in which the carboxyl group of poly (2-carboxyethylsiloxane) is protected with an acid-dissociable group such as t-butyl group (for example, Patent Document 2) And a resist resin composition using a polyorganosilsesquioxane having an acid dissociable ester group (for example, see Patent Document 3). However, resist materials using these conventional acid-dissociable group-containing siloxane polymers are still not at a satisfactory level in terms of basic physical properties as resists such as transparency to radiation, resolution, and developability. .

Further, it has a non-aromatic monocyclic, polycyclic or bridged cyclic hydrocarbon group having a carboxyl group in the side chain, and at least a part of the carboxyl group is substituted with an acid labile group. A siloxane-based polymer and a resist material using the polymer have been reported (for example, see Patent Document 4). This resist material has low absorption of KrF excimer laser and ArF excimer laser, and has a good pattern shape. It is also said to be excellent in sensitivity, resolution, dry etching resistance and the like.
On the other hand, some resist materials using a fluorocarbon-based polymer having a fluorine atom in the main chain or side chain have already been reported. This polymer is also excellent in transparency at a wavelength of 200 nm or less, particularly at a wavelength of 157 nm, and is 193 nm or less. It is reported that it is suitable for a resist material in a lithography process using a wavelength of (see, for example, Patent Document 5 and Patent Document 6).
However, in the case of the siloxane polymer and the fluorocarbon polymer, it cannot be said that the solubility in the developer reaches a sufficient level as compared with the conventional aromatic polymer.

J. Photopolym. Sci. Technol., Vol.12, No.4, P.561-570 (1999) Japanese Patent Laid-Open No. 5-323611 JP-A-8-160623 Japanese Patent Laid-Open No. 11-60733 JP-A-11-302382 WO 02/065212 A1 WO 03/006413 A1

  Therefore, development of a new polymer capable of providing a resist material that is sensitive to radiation with a wavelength of 200 nm or less, has high dry etching resistance, has excellent basic physical properties as a resist, and has excellent solubility in an alkaline developer. Is an important issue from the viewpoint of technological development that can cope with rapid progress in miniaturization in the LSI field.

An object of the present invention is to effectively respond to radiation having a wavelength of 200 nm or less typified by ArF excimer laser (wavelength 193 nm) or F ₂ excimer laser (wavelength 157 nm), have high transparency to radiation, excellent resolution, and resin A radiation-sensitive resin composition useful as a chemically amplified resist having excellent solubility in an alkaline developer of the component, easy control of the solubility, and excellent sensitivity, dry etching resistance, and the like. It is an object of the present invention to provide a novel fluorine-containing vinyl ether polymer useful as a resin component of a radiation resin composition.

The present invention, first,
It has a repeating unit represented by the following general formula (I), and is a ratio (%) of [—OR group where R is a monovalent acid-dissociable group] to [total amount of —OR groups in the polymer]. Polymer having a polystyrene-reduced weight average molecular weight of 500 to 1,000,000 by gel permeation chromatography (GPC), wherein the introduction rate of the defined monovalent acid dissociable group is 9.0% or more and 26% or less ( Hereinafter, it is referred to as “polymer (A)”.

〔一般式（Ｉ）において、各Ｒは相互に独立に水素原子またはメチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、２−メチルプロピル基、１−メチルプロピル基、ｔ−ブチル基、ｎ−ペンチル基、ｎ−ヘキシル基、ｎ−ヘプチル基、ｎ−オクチル基、ｎ−デシル基、シクロペンチル基、シクロヘキシル基、４−ｔ−ブチルシクロヘキシル基、シクロヘプチル基もしくはシクロオクチル基からなるアルキル基；メトキシカルボニル基、エトキシカルボニル基、ｉ−プロポキシカルボニル基、ｉ−ブチルカルボニル基、ｔ−ブトキシカルボニル基、９−フルオレニルメチルカルボニル基、２，２，２−トリクロロエチルカルボニル基、２−（トリメチルシリル）エチルカルボニル基、ビニルカルボニル基、アリルカルボニル基、ベンジルカルボニル基、４−エトキシ−１−ナフチルカルボニル基もしくはメチルジチオカルボニル基からなる有機カルボニル基；あるいはメトキシメチル基、エトキシメチル基、２−フルオロエトキシメチル基、ｔ−ブトキシメチル基、ベンジルオキシメチル基、２−メトキシエトキシメチル基、トリメチルシロキシメチル基、トリエチルシロキシメチル基、１−エトキシエチル基もしくは１−メチル−１−メトキシエチル基からなる、Ｒが結合している酸素原子と共にアセタール基もしくはケタール基を形成する有機基の群より選ばれる１価の酸解離性基を示す。〕

[In General Formula (I), each R is independently a hydrogen atom or a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, or a 1-methylpropyl group. , T-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-decyl group, cyclopentyl group, cyclohexyl group, 4-t-butylcyclohexyl group, cycloheptyl group or cyclo Alkyl group consisting of octyl group; methoxycarbonyl group, ethoxycarbonyl group, i-propoxycarbonyl group, i-butylcarbonyl group, t-butoxycarbonyl group, 9-fluorenylmethylcarbonyl group, 2,2,2-trichloroethyl Carbonyl group, 2- (trimethylsilyl) ethylcarbonyl group, vinylcarbonyl group, allylcarbonyl An organic carbonyl group consisting of benzylcarbonyl group, 4-ethoxy-1-naphthylcarbonyl group or methyldithiocarbonyl group; or methoxymethyl group, ethoxymethyl group, 2-fluoroethoxymethyl group, t-butoxymethyl group, benzyloxymethyl Group, 2-methoxyethoxymethyl group, trimethylsiloxymethyl group, triethylsiloxymethyl group, 1-ethoxyethyl group or 1-methyl-1-methoxyethyl group, together with an oxygen atom to which R is bonded, an acetal group or a ketal 1 represents a monovalent acid dissociable group selected from the group of organic groups forming the group . ]

The present invention secondly,
(A) Among the polymers (A), an alkali-insoluble or hardly-alkaline-soluble polymer that becomes readily soluble when the acid-dissociable group is dissociated, and (b) generation of a radiation-sensitive acid. It comprises a radiation sensitive resin composition characterized by containing an agent.

Hereinafter, the present invention will be described in detail.
Polymer (A)
The polymer (A) in the present invention is a polymer having a repeating unit represented by the general formula (I) (hereinafter referred to as “repeating unit (I)”).

Of the monovalent acid-dissociable groups represented by R in the general formula (I) , a methoxymethyl group, an ethoxymethyl group, a 2-fluoroethoxymethyl group, a t-butoxymethyl group, and the like are preferable.
In the polymer (A), the repeating unit (I) may be present alone or in combination of two or more.

The polymer (A) can have a repeating unit other than the repeating unit (I) (hereinafter referred to as “other repeating unit”).
Examples of other repeating units include:
Α, α-disubstituted olefins such as 2-methylpropene; conjugated dienes such as butadiene and isoprene; aromatics such as styrene, α-methylstyrene, 4-methylstyrene, 4-methoxystyrene 4-t-butoxystyrene Vinyl compounds: methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, methoxyethylene glycol monovinyl ether, ethoxyethylene glycol monovinyl ether, methoxydiethylene glycol monovinyl ether Linear or branched vinyl such as ethoxydiethylene glycol monovinyl ether, 2-chloroethyl vinyl ether, 2-bromoethyl vinyl ether Ether such; 2,3-dihydrofuran, 3,4-polymerizable unsaturated bond such as cyclic 5,717,036 dihydro -2H- pyran or the like can be exemplified repeating units cleaved.

Among these other repeating units, a repeating unit in which a polymerizable unsaturated bond such as 2,3-dihydrofuran or 3,4-dihydro-2H-pyran is cleaved is preferable.
In the polymer (A), other repeating units may be present alone or in combination of two or more.

In the polymer (A), the molecular weight and glass transition temperature (Tg) of the obtained polymer (A) can be controlled by appropriately selecting or appropriately combining other repeating units. The transparency at a wavelength of 157 nm can be further improved.
The specific content of each repeating unit in the polymer (A) is not particularly limited and varies depending on the type and combination of the repeating units, the use of the polymer (A), etc. A suitable content of each repeating unit can be appropriately selected by a person skilled in the art by a test or the like.
For example, the polymer (A) is a chemically amplified resist for fine processing using radiation such as far ultraviolet rays, X-rays, and electron beams, and is itself insoluble or hardly soluble in alkali, and its acid-dissociable group is dissociated. When used as a resin component that is readily soluble in alkali, the content of the repeating unit (I) is preferably 40 to 95 mol%, more preferably 50 to 90 mol%, based on all structural units. . In this case, if the content of the repeating unit (I) is less than 40 mol%, the solubility of the resulting polymer in an alkali developer tends to be reduced, whereas if it exceeds 95 mol%, the resulting weight is increased. There exists a tendency for the glass transition temperature (Tg) of a coalescence to fall.

The polystyrene equivalent weight average molecular weight (hereinafter referred to as “Mw”) measured by gel permeation chromatography (GPC) of the polymer (A) is 500 to 1,000,000, preferably 500 to 100,000, particularly preferably. Is 1000 to 10,000. In this case, if the Mw is less than 500, the glass transition temperature (Tg) of the resulting polymer tends to decrease, whereas if it exceeds 1,000,000, the solubility of the resulting polymer in the solvent is low. There is a tendency to decrease.
The ratio (Mw / Mn) of the polymer (A) Mw and the polystyrene-equivalent number average molecular weight (hereinafter referred to as “Mn”) measured by gel permeation chromatography (GPC) is usually 1 to 5, Preferably it is 1-3.

The polymer (A) has characteristics that it is highly transparent to radiation having a wavelength of 200 nm or less, has high solubility in an alkaline developer, and can easily control the solubility.
Among the polymers (A), an alkali-insoluble or hardly alkali-soluble polymer that becomes alkali-soluble when the acid-dissociable group is dissociated is radiation such as far ultraviolet rays, X-rays, and electron beams. It can be used very suitably as a resin component in a radiation sensitive resin composition useful as a chemically amplified resist for microfabrication.
In addition, the polymer (A) has extremely high solubility in lower alcohols such as ethanol and i-propanol, and as a solution dissolved in the lower alcohols, it is extremely useful for forming an upper antireflection film in a lithography process. It is.

  The polymer (A) is, for example, a polymerizable unsaturated unit that gives a monomer represented by the following formula (a) (hereinafter referred to as “monomer (a)”) as the case may be. A precursor polymer is obtained by cation polymerization according to a conventional method in the presence of a cationic polymerization initiator, in the absence of a solvent or in a solvent, together with a monomer, and then a hydrogen atom of a hydroxyl group in the precursor polymer is converted by a conventional method. It can be produced by a method of substitution with a monovalent acid dissociable group (R).

Hereinafter, the method for producing the polymer (A) will be described.
Examples of the cationic polymerization initiator include proton acids such as sulfuric acid, hydrochloric acid, trifluoroacetic acid, trichloroacetic acid, trifluoromethanesulfonic acid, trichloromethanesulfonic acid, fluorosulfonic acid, and perchloric acid; boron trifluoride diethyl ether complex Metal halides such as aluminum chloride, titanium tetrachloride, tin tetrachloride, antimony pentachloride, molybdenum pentachloride and ferric chloride and their complexes; organics such as ethylaluminum dichloride, diethylaluminum chloride, trimethylaluminum and triethylaluminum A metal compound etc. can be mentioned.
Of these cationic polymerization initiators, boron trifluoride diethyl ether complex, titanium tetrachloride, tin tetrachloride, ethylaluminum dichloride and the like are preferable.
The cationic polymerization initiators can be used alone or in admixture of two or more. The usage-amount of a cationic polymerization initiator is 0.0001-1 weight part normally with respect to 100 weight part of whole quantity of a monomer, Preferably it is 0.001-0.01 weight part.

Examples of the solvent include aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, and n-octane; aromatic hydrocarbons such as benzene, toluene, and xylene; carbon tetrachloride, chloroform And halogenated hydrocarbons such as dichloromethane and dichloroethane.
Of these solvents, n-hexane, toluene, dichloromethane and the like are preferable.
As for the reaction conditions for the cationic polymerization, the reaction temperature is usually −100 to 0 ° C., preferably −80 to −50 ° C., and the reaction time is usually 1 to 50 hours, preferably 5 to 10 hours.

Radiation-sensitive resin composition The radiation-sensitive resin composition of the present invention is (a) a polymer that is alkali-insoluble or alkali-insoluble in polymer (A), and its acid-dissociable group is dissociated. And (b) a radiation-sensitive acid generator (hereinafter referred to as “acid generator (B)”).
The term “alkali insoluble or alkali poorly soluble” as used herein refers to an alkali developing condition employed when a resist pattern is formed from a resist film formed from a radiation-sensitive resin composition containing the polymer (A). When a resist film using only the polymer (A) is developed instead of the resist film, it means that 50% or more of the initial film thickness of the film remains after development.

-Polymer (A)-
In the radiation sensitive resin composition of the present invention, the polymer (A) can be used alone or in admixture of two or more, and one or more other polymers can be used together with the polymer (A). It can also be used together.
Examples of the other polymer include, in addition to the other repeating units exemplified for the polymer (A), methyl (meth) acrylate, ethyl (meth) acrylate, t-butyl (meth) acrylate, (meth ) (Meth) acrylic acid esters such as cyclohexyl acrylate; vinyl cyanide compounds such as (meth) acrylonitrile; unsaturated imides such as maleimide, N-phenylmaleimide, N-cyclohexylmaleimide; bicyclo [2.2.1 ] Hept-2-ene, tetracyclo [6.2.1.1 ^3,6 . 0 ^2,7 ] A heavy polymer having one or more repeating units in which a polymerizable unsaturated bond is cleaved, such as a polymerizable unsaturated monomer having a bridged carbocyclic structure such as dodec-4-ene and substituted derivatives thereof. Coalescence can be mentioned.

-Acid generator (B)-
The acid generator (B) in the radiation-sensitive resin composition of the present invention generates an acid upon exposure and dissociates the acid-dissociable group present in the polymer (A) by the action of the acid, resulting in a resist The exposed portion of the film is a component having an action of forming a positive resist pattern by being easily soluble in an alkali developer.
In the present invention, the acid generator (B) is not particularly limited as long as it has the above action. For example, an onium salt compound, a sulfone compound, a sulfonic acid compound, a carboxylic acid compound, a diazoketone compound, a halogen-containing compound, etc. Can be mentioned.

As a preferable acid generator (B) in the present invention, for example,
Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2- (bicyclo [2.2.1] heptan-2-yl) -1,1, 2,2-tetrafluoroethanesulfonate, diphenyliodonium 2- (tetracyclo [6.2.1.1 ^3,6 .0 ^2,7 ] dodecan-4-yl) -1,1,2,2-tetrafluoroethane Sulfonate, diphenyliodonium N, N-bis (nonafluoro-n-butanesulfonyl) imidate, diphenyliodonium 10-camphorsulfonate,
Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, Bis (4-t-butylphenyl) iodonium 2- (bicyclo [2.2.1] heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) Iodonium 2- (tetracyclo [6.2.1.1 ^3,6 0.0 ^2,7 ] dodecan-4-yl) -1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) ) Iodonium N, N-bis (nonafluoro-n-butanesulfonyl) imidate, bis (4-t-butylphenol) Le) iodonium 10-camphorsulfonate,

Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2- (bicyclo [2.2.1] heptan-2-yl)- 1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2- (tetracyclo [6.2.1.1 ^3,6 .0 ^2,7 ] dodecan-4-yl) -1,1,2, 2-tetrafluoroethanesulfonate, triphenylsulfonium N, N-bis (nonafluoro-n-butanesulfonyl) imidate, triphenylsulfonium 10-camphorsulfonate,
1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2- (bicyclo [2.2 .1] Heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2- (tetracyclo [6.2. 1.1 ^3,6 .0 ^2,7] dodecane-4-yl) -1,1,2,2-tetrafluoro et drawers Phonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium N, N-bis (nonafluoro-n-butanesulfonyl) imidate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydro Thiophenium 10-camphorsulfonate,

1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (3,5-Dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (bicyclo [2.2 .1] Heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (tetracyclo [6.2. 1.1 ^3,6 .0 ^2,7] dodecane-4-yl) -1,1,2,2 Te Lafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium N, N-bis (nonafluoro-n-butanesulfonyl) imidate, 1- (3,5-dimethyl-4-hydroxy Phenyl) tetrahydrothiophenium 10-camphorsulfonate,
N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- [2- (bicyclo [2.2.1] ] heptan-2-yl) 1,1,2,2-tetrafluoroethane sulfonyloxy] succinimide, N- [2- (tetracyclo [6.2.1.1 ^3,6 .0 ^2,7] dodecane - 4-yl) -1,1,2,2-tetrafluoroethanesulfonyloxy] succinimide, N- (10-camphorsulfonyloxy) succinimide,

N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept -5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- [ 2- (Bicyclo [2.2.1] heptan-2-yl) -1,1,2,2-tetrafluoroethanesulfonyloxy] bicyclo [2.2.1] hept-5-ene-2,3- dicarboximide, N- [2- (tetracyclo [6.2.1.1 ^3,6 .0 ^2,7] dodecane-4-yl) 1,1,2,2-tetrafluoroethane sulfonyloxy] bicyclo [2.2 1] Hept-5-ene-2,3-dicarboximide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, etc. Can do.

In this invention, an acid generator (B) can be used individually or in mixture of 2 or more types.
The amount of the acid generator (B) used is usually from 0.1 to 10 parts by weight, preferably from 0.1 to 10 parts by weight, based on 100 parts by weight of the total amount of the polymer components, from the viewpoint of ensuring sensitivity and developability as a resist. 5 to 7 parts by weight. In this case, if the amount of the acid generator (B) used is less than 0.1 parts by weight, the sensitivity and developability tend to decrease. On the other hand, if it exceeds 10 parts by weight, the transparency to radiation decreases and the rectangular shape is reduced. It tends to be difficult to obtain a resist pattern.

-Additives-
Various additives such as an acid diffusion controller, a dissolution controller, and a surfactant can be blended with the radiation-sensitive resin composition of the present invention.
The acid diffusion control agent is a component having an action of controlling a diffusion phenomenon of an acid generated from an acid generator upon exposure in a resist film and suppressing an undesirable chemical reaction in a non-exposed region.
By blending such an acid diffusion control agent, the storage stability of the resulting radiation-sensitive resin composition is further improved, the resolution as a resist is further improved, and the holding time from exposure to development processing A change in the line width of the resist pattern due to fluctuations in (PED) can be suppressed, and a composition having excellent process stability can be obtained.
As the acid diffusion controller, a nitrogen-containing organic compound whose basicity is not changed by exposure or heat treatment in the resist pattern forming step is preferable.
Such nitrogen-containing organic compounds include, for example, compounds represented by the following general formula (1) (hereinafter referred to as “acid diffusion controller (C)”), quaternary ammonium hydroxide compounds, amide groups. Examples thereof include a containing compound, a urea compound, and a nitrogen-containing heterocyclic compound.

〔一般式（１）において、各Ｒ¹ は相互に独立に水素原子、直鎖状、分岐状もしくは環状のアルキル基、アリール基またはアラルキル基を示し、これらのアルキル基、アリール基およびアラルキル基は水酸基等の官能基で置換されていてもよく、Ｕ¹ は２価の有機基を示し、ｒは０〜２の整数である。〕

[In the general formula (1), each R ¹ independently represents a hydrogen atom, a linear, branched or cyclic alkyl group, aryl group or aralkyl group, and these alkyl group, aryl group and aralkyl group are It may be substituted with a functional group such as a hydroxyl group, U ¹ represents a divalent organic group, and r is an integer of 0 to 2. ]

  In the acid diffusion controller (C), the compound with r = 0 is referred to as “nitrogen-containing compound (C1)”, and the compound with r = 1 to 2 is referred to as “nitrogen-containing compound (C2)”. Further, the polyamino compound and polymer having 3 or more nitrogen atoms are collectively referred to as “nitrogen-containing compound (C3)”.

  Examples of the nitrogen-containing compound (C1) include mono- (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n- Butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. Di (cyclo) alkylamines; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine , Tri-n-nonylamine, tri-n-decylamine, cyclohexyl Tri (cyclo) alkylamines such as dimethylamine, dicyclohexylmethylamine, tricyclohexylamine; alkanolamines such as ethanolamine, diethanolamine, triethanolamine; aniline, N-methylaniline, N, N-dimethylaniline, 2 -Aromatic amines such as methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, 2,6-dimethylaniline, 2,6-diisopropylaniline, diphenylamine, triphenylamine, naphthylamine, etc. Can do.

Examples of the nitrogen-containing compound (C2) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine, tetramethylenediamine, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzenetetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′- Diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) ) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxy) Droxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene, Examples thereof include bis (2-dimethylaminoethyl) ether and bis (2-diethylaminoethyl) ether.
Examples of the nitrogen-containing compound (C3) include polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer, and the like.

Examples of the quaternary ammonium hydroxide compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-propylammonium hydroxide, and tetra-n-butylammonium hydroxide.
Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, N -T-butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-1-adamantyl Amine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′-diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylene Diamine, N, N, N ′, N′-tetra-t-butoxycarbonylhexame Range amine, N, N′-di-t-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t- Butoxycarbonyl-1,9-diaminononane, N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N, N '-Di-t-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenz Nt-butoxycarbonyl group-containing amino compounds such as imidazole, formamide, N-methylformamide, N, N-di Chill formamide, acetamide, N- methylacetamide, N, N- dimethylacetamide, propionamide, benzamide, pyrrolidone, can be mentioned N- methylpyrrolidone.

Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n. -Butylthiourea etc. can be mentioned.
Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, 4-methylimidazole, 1-benzyl-2-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, and 2-phenylbenzimidazole. Pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide , Pyridines such as quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine; piperazines such as piperazine, 1- (2-hydroxyethyl) piperazine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidin , 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1,4-dimethylpiperazine, and 1,4-diazabicyclo [2.2.2] octane.

These acid diffusion control agents can be used alone or in admixture of two or more.
The compounding amount of the acid diffusion controller is usually 100 mol% or less, preferably 50 mol% or less, and more preferably 30 mol% or less with respect to the acid generator (B). In this case, when the compounding amount of the acid diffusion control agent exceeds 100 mol%, the sensitivity as a resist and the alkali developability of the exposed area tend to decrease. If the amount of the acid diffusion controller is less than 0.1 mol%, the pattern shape or dimensional fidelity as a resist may be lowered depending on the process conditions.

Examples of the dissolution control agent include:
Adamantane-1-carboxylic acid t-butyl, adamantane-1-carboxylic acid t-butoxycarbonylmethyl, adamantane-1-carboxylic acid α-butyrolactone ester, adamantane-1,3-dicarboxylic acid di-t-butyl, adamantane-1 T-butyl acetate, adamantane-1-t-butoxycarbonylmethyl acetate, adamantane-1,3-diacetate di-t-butyl, 2,5-dimethyl-2,5-di (adamantan-1-ylcarbonyloxy Adamantane derivatives such as hexane;
Deoxycholate t-butyl, deoxycholate t-butoxycarbonylmethyl, deoxycholate 2-ethoxyethyl, deoxycholate 2-cyclohexyloxyethyl, deoxycholate 3-oxocyclohexyl, deoxycholate tetrahydropyranyl, deoxychol Deoxycholic acid esters such as acid mevalonolactone ester;
Lithocholic acid t-butyl, lithocholic acid t-butoxycarbonylmethyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2-cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester, etc. Lithocholic acid esters:
Examples thereof include alkyl carboxylic acid esters such as dimethyl adipate, diethyl adipate, propyl at the time of adipic acid, di-n-butyl adipate, and di-t-butyl adipate.

These dissolution control agents can be used alone or in admixture of two or more.
The blending amount of the dissolution control agent is usually 50 parts by weight or less, preferably 30 parts by weight or less with respect to 100 parts by weight of the total amount of the polymer components. In this case, when the compounding amount of the dissolution control agent exceeds 50 parts by weight, the heat resistance as a resist tends to decrease.

The surfactant is a component having an action of improving coating properties, striations, developability and the like.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. In addition to nonionic surfactants such as polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Tochem Products Co., Ltd.), Megafax F171, F173 (above, Dainippon Ink & Chemicals, Inc.) ), Florard FC430, FC431 (above, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC -105, SC-106 (above, manufactured by Asahi Glass Co., Ltd.) and the like.
These surfactants can be used alone or in admixture of two or more.
The compounding amount of the surfactant is usually 2 parts by weight or less with respect to 100 parts by weight of the total amount of the polymer components.
Examples of additives other than those described above include antihalation agents, adhesion assistants, storage stabilizers, and antifoaming agents.

-Preparation of composition solution-
The radiation-sensitive resin composition of the present invention is usually dissolved in a solvent so that the total solid content is usually 1 to 25% by weight, preferably 2 to 15% by weight. A composition solution is prepared by filtering with a filter having a pore size of about 0.2 μm.
Examples of the solvent used for the preparation of the composition solution include:
2-butanone, 2-pentanone, 3-methyl-2-butanone, 2-hexanone, 4-methyl-2-pentanone, 3-methyl-2-pentanone, 3,3-dimethyl-2-butanone, 2-heptanone, Linear or branched ketones such as 2-octanone;
Cyclic ketones such as cyclopentanone, 3-methylcyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, isophorone;
Propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-i-propyl ether acetate, propylene glycol mono-n-butyl ether acetate, propylene glycol mono-i-butyl ether acetate Propylene glycol monoalkyl ether acetates such as propylene glycol mono-sec-butyl ether acetate, propylene glycol mono-t-butyl ether acetate;

Methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, n-propyl 2-hydroxypropionate, i-propyl 2-hydroxypropionate, n-butyl 2-hydroxypropionate, i-butyl 2-hydroxypropionate, Alkyl 2-hydroxypropionates such as sec-butyl 2-hydroxypropionate and t-butyl 2-hydroxypropionate;
Alkyl 3-alkoxypropionates such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate,

2,3-difluorobenzyl alcohol, 2,2,2-trifluoroethanol, 1,3-difluoro-2-propanol, 1,1,1-trifluoro-2-propanol, 3,3,3-trifluoro -1-propanol, 2,2,3,3,4,4,4-heptafluoro-1-butanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, 3,3,4,4,5,5,5-heptafluoro-2-pentanol, 1H, 1H-perfluoro-1-octanol, 1H, 1H, 2H, 2H-perfluoro-1-octanol, 1H, 1H, 9H-perfluoro-1-nonanol, 1H, 1H, 2H, 3H, 3H-perfluorononane-1,2-diol, 1H, 1H, 2H, 2H-perfluoro-1-decanol, 1H, H, 2H, 3H, fluorine-containing alcohols such as 3H- perfluoro undecanoic 1,2-diol;

2,2,2-trifluoroethyl butyrate, ethyl heptafluorobutyrate, ethyl heptafluorobutyl acetate, ethyl hexafluoroglutarate, ethyl-3-hydroxy-4,4,4-trifluorobutyrate, ethyl-2 -Methyl-4,4,4-trifluoroacetoacetate, ethyl pentafluorobenzoate, ethyl pentafluoropropionate, ethyl pentafluoropropionate, ethyl perfluorooctanoate, ethyl-4,4,4-trifluoroacetate Acetate, ethyl-4,4,4-trifluorobutyrate, ethyl-4,4,4-trifluorocrotonate, ethyl trifluorosulfonate, ethyl-3- (trifluoromethyl) butyrate, ethyl trifluoropyruvate, Ethyl trifluoroa Tate, isopropyl-4,4,4-trifluoroacetoacetate, methyl perfluorodecanoate, methyl perfluoro (2-methyl-3-oxahexanoate), methyl perfluorononanoate, methyl perfluorooctanoate Methyl-2,3,3,3-tetrafluoropropionate, methyltrifluoroacetoacetate, methyltrifluoroacetoacetate, perfluoro (2,5,8-trimethyl-3,6,9-trioxadodecanoic acid ) Methyl, propylene glycol trifluoromethyl ether acetate, propylene glycol methyl ether trifluoromethyl acetate, n-butyl trifluoromethyl acetate, methyl 3-trifluoromethoxypropionate, 1,1,1-trifluoro-2-propiate Acetate, fluorine-containing esters such as n- butyl trifluoroacetate;

2-fluoroanisole, 3-fluoroanisole, 4-fluoroanisole, 2,3-difluoroanisole, 2,4-difluoroanisole, 2,5-difluoroanisole, 5,8-difluoro-1,4-benzodioxane, tri Fluoroacetaldehyde ethyl hemiacetal, 2H-perfluoro (5-methyl-3,6-dioxanonane), 2H-perfluoro (5,8,11,14-tetramethyl-3,6,9,12,15-pentaoxa Fluorine-containing ethers such as octadecane), (perfluoro-n-butyl) tetrahydrofuran, perfluoro (n-butyltetrahydrofuran), propylene glycol trifluoromethyl ether;

2,4-difluoropropiophenone, fluorocyclohexane, 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedione, 1,1,1,3 5,5,5-heptafluoropentane-2,4-dione, 3,3,4,4,5,5,5-heptafluoro-2-pentanone, 1,1,1,2,2,6,6 Fluorine-containing ketones such as 1,6-octafluoro-2,4-hexanedione, trifluorobutanol-1,1,1-trifluoro-5-methyl-2,4-hexanedione, and perfluorocyclohexanone;
In addition to fluorine-containing solvents such as fluorine-substituted cyclic hydrocarbons such as 2,4-difluorotoluene, perfluorodecalin, perfluoro (1,2-dimethylcyclohexane), perfluoro (1,3-dimethylcyclohexane),

n-propanol, i-propanol, n-butanol, t-butanol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, propylene glycol monomethyl ether, propylene glycol mono Ethyl ether, propylene glycol Mono-n-propyl ether, toluene, xylene, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl- 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl acetoacetate, ethyl acetoacetate, Methyl pyruvate, ethyl pyruvate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, benzyl ethyl ether, di-n-hexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether , Caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, ethyl benzyl acetate, benzoate, diethyl oxalate, diethyl maleate, .gamma.-butyrolactone, ethylene carbonate, propylene carbonate and the like.

  These solvents can be used alone or in admixture of two or more, but in particular, linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, 2- Alkyl hydroxypropionates, alkyl 3-alkoxypropionates, fluorine-containing solvents and the like are preferable.

Formation method of resist pattern In the formation process of the resist pattern using the radiation sensitive resin composition of the present invention, an acid is generated from the acid generator (B) by exposure, and the action of the acid causes the polymer (A) The acid-dissociable group of the acid is dissociated to form an alcoholic hydroxyl group, and as a result, the solubility of the exposed portion of the resist in the alkaline developer is increased, and the exposed portion is dissolved and removed by the alkaline developer. A resist pattern is obtained.

When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution is coated with, for example, a silicon wafer or aluminum by an appropriate application means such as spin coating, cast coating or roll coating. In order to form a predetermined resist pattern after a resist film is formed by applying a heat treatment (hereinafter referred to as “PB”) in advance in some cases. Then, the resist film is exposed.
The radiation used at this time is an ArKr excimer laser (wavelength 134 nm), a Kr ₂ excimer laser (wavelength 147 nm), an F ₂ excimer laser (wavelength 157 nm), an ArF excimer laser (wavelength 193 nm), or a KrF excimer laser (wavelength 248 nm). ) Is preferred.
In the present invention, it is preferable to perform heat treatment (hereinafter referred to as “PEB”) after exposure. By this PEB, the dissociation reaction of the acid dissociable group in the polymer (A) proceeds smoothly. The heating condition of PEB varies depending on the composition of the radiation sensitive resin composition, but is usually 30 to 200 ° C, preferably 50 to 170 ° C.

  As the lower layer film, for example, an organic or inorganic lower layer film as described in Patent Document 7 can be cited, and in order to prevent the influence of basic impurities contained in the environmental atmosphere, a resist is used. A protective film can be provided on the coating, or both a lower layer film and a protective film can be provided (see, for example, Patent Document 8).

Japanese Examined Patent Publication No. 6-12458 JP-A-5-188598

Next, the exposed resist film is preferably developed with an alkali developer to form a predetermined resist pattern.
Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, Methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4. 3.0] An alkaline aqueous solution in which at least one alkaline compound such as 5-nonene is dissolved is preferable.
The concentration of the alkaline aqueous solution is usually 10% by weight or less. In this case, if the concentration of the alkaline aqueous solution exceeds 10% by weight, the unexposed portion of the resist film may be dissolved in the developer, which is not preferable.

In addition, for example, an organic solvent can be added to the alkaline developer.
Examples of the organic solvent include ketones such as acetone, 2-butanone, 4-methyl-2-pentanone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methanol, ethanol, alcohols such as n-propanol, i-propanol, n-butanol, t-butanol, cyclopentanol, cyclohexanol, 1,4-hexanediol and 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane; Examples thereof include esters such as ethyl acetate, n-butyl acetate and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone and dimethylformamide.
These organic solvents can be used alone or in admixture of two or more.
The amount of the organic solvent used is preferably 100% by volume or less with respect to the alkaline aqueous solution. In this case, when the amount of the organic solvent used exceeds 100% by volume, the developability is lowered, and there is a possibility that the remaining development in the exposed area increases.
An appropriate amount of a surfactant or the like can be added to the alkaline developer.
In addition, after developing with an alkali developing solution, it is generally washed with water and dried.

  The polymer (A) of the present invention is particularly suitably used as a resin component in a radiation-sensitive resin composition useful as a chemically amplified resist for fine processing using radiation such as far ultraviolet rays, X-rays, and electron beams. In addition, it has extremely high solubility in lower alcohols and is extremely useful as a resin component of the upper antireflection film.

  The radiation-sensitive resin composition of the present invention using the polymer (A) as a resin component is effectively sensitive to radiation having a wavelength of 200 nm or less, has high transparency to radiation, has excellent resolution, and is an alkaline developer of the resin component. It is useful as a chemically amplified resist that excels in solubility, is easy to control, and has excellent sensitivity, dry etching resistance, etc. In particular, LSIs that are expected to become increasingly finer in the future. It can be used very suitably for the production of

Hereinafter, the embodiment of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
Measurement and evaluation of each polymer obtained in Synthesis Examples 1 to 8 and Examples 1 to 8 were performed as follows.
Mw:
Using a GPC column (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation, monodisperse polystyrene as the standard under the analysis conditions of flow rate 1.0 ml / min, elution solvent tetrahydrofuran, column temperature 40 ° C. Measured by gel permeation chromatography (GPC).
Absorption coefficient:
Each polymer was dissolved in 2-heptanone to prepare a resin solution with a solid concentration of 5% by weight, and then each resin solution was applied onto a magnesium fluoride substrate by spin coating and maintained at 110 ° C or 140 ° C. A film having a thickness of 1,000 mm was formed by heating on a hot plate for 90 seconds. Then, the extinction coefficient in wavelength 157nm and wavelength 193nm was measured about each coating film. When the extinction coefficient at a wavelength of 157 nm is 1.5 μm ⁻¹ or less, and when the extinction coefficient at a wavelength of 193 nm is 0.5 μm ⁻¹ or less, it can be said that the transparency to each wavelength is good.

Synthesis Examples 1-8 (Synthesis of precursor polymer)
Into a three-necked flask equipped with a stirrer, thermometer, and three-way stopcock, a monomer shown in Table 1 and an amount of toluene shown in Table 1 were charged in a nitrogen atmosphere, and then the reaction vessel was dried while stirring. The contents were cooled to -78 ° C in ice-methanol. Then, using a microsyringe, boron trifluoride diethyl ether complex (BF ₃ OEt ₂ ) was added as a cationic polymerization initiator in the amount shown in Table 1, and the reaction was allowed to proceed for the time shown in Table 1. Thereafter, 5 ml of a 2 wt% methanol solution of ammonia was added to the reaction solution to stop the reaction. Thereafter, the reaction solution is transferred to a separating funnel while adding 100 ml of methyl isobutyl ketone (MIBK), washed with a 2% by weight aqueous sodium thiosulfate solution, and further washed with a 1.75% by weight aqueous oxalic acid solution, followed by ion exchange. Water was added and washed, and washing was repeated until the reaction solution became neutral. Thereafter, the organic layer was distilled off under reduced pressure to obtain each precursor polymer. Table 1 shows the yield, Mw and extinction coefficient of each precursor polymer.

In Table 1, monomer (a-1), monomer (b-1) and monomer (b-2) are as follows.
a-1: Compound represented by the following formula (4) b-1: 3,4-dihydro-2H-pyran b-2: 2,3-dihydrofuran

Examples 1 to 8 (Synthesis of polymer (A))
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer, and dropping funnel, 2 g of each of the precursor polymers obtained in Synthesis Examples 5 to 8, and methanol in the amounts shown in Table 2 (however, some Example) and a 28 wt% methanol solution of sodium methoxide (CH ₃ ONa) were added, followed by stirring at room temperature for 4 hours. Then, after cooling the reaction solution with ice, the amount of chloromethyl ethyl ether (ClCH ₂ OEt) shown in Table 2 was added dropwise over 1 hour, and reacted at room temperature for 4 hours after the addition was completed. The hydrogen atom of the hydroxyl group was replaced with an ethoxymethyl group. Thereafter, the reaction solution was concentrated to a solid content concentration of about 60% by weight, transferred to a separatory funnel, and washed with 50 ml of MIBK and 50 ml of an aqueous 1.75% by weight oxalic acid solution. Thereafter, the aqueous layer was removed, and the organic layer was washed with distilled water until the washing water became neutral, and then concentrated under reduced pressure to obtain a polymer (A). Table 2 shows the yield, Mw, and extinction coefficient of each polymer (A).
Moreover, about each polymer (A), while measuring the < ¹ > H-NMR spectrum and < ¹³ > C-NMR spectrum, the structure was confirmed and the introduction rate of the acid dissociable group (ethoxymethyl group) was calculated. The results are shown in Table 2. Here, the introduction rate of the acid dissociable group means the ratio (%) of the hydroxyl group in which the ethoxymethyl group is introduced with respect to the total amount of the hydroxyl group in the repeating unit (I) derived from the monomer (a-1). To do.

Examples 9 to 17 (Evaluation of radiation sensitive resin composition)
With respect to 100 parts by weight of each of the polymers (A) obtained in Examples 1 to 8, 8 mol% of 2- (2-mol) was added to the total amount of the acid generator (B) and acid generator (B) shown in Table 3. After adding the solvent shown in Table 3 to the mixture to which phenylbenzimidazole was added and dissolving, it was filtered through a membrane filter having a pore size of 0.45 μm to prepare a composition solution.
Next, each composition solution was applied by spin coating on a substrate on which an antireflection film DUV-30 (trade name, manufactured by Brewer Science) was formed on the surface, and then PB for 90 seconds on a hot plate maintained at 100 ° C. And a resist film having a thickness of 1,200 mm was formed. Thereafter, when each resist film is exposed with an ArF excimer laser (wavelength 193 nm) (indicated as “ArF” in Table 3), Nikon Corporation S306C (numerical aperture 0.75, spatial coherence factor ( σ) 0.85, 2/3 annular illumination), and when exposure is performed with an F ₂ excimer laser (wavelength 157 nm) (indicated as “F2” in Table 3), 157 nm Exposure tool (exittech) Each of the excimer lasers was exposed with a different exposure amount through a reticle using a numerical aperture of 0.85 and σ of 0.3). Thereafter, PEB was performed for 90 seconds on a hot plate maintained at 100 ° C., then developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution, washed with water, dried, and line and space pattern ( 1L1S) was formed.
At this time, the minimum dimension of the line-and-space pattern (1L1S) resolved when exposed with the optimum depth of focus and the optimum exposure amount was measured to evaluate the resolution. The evaluation results are shown in Table 3.

The acid generator (B) and the solvent in Table 3 are as follows.
Acid generator (B)
B-1: Triphenylsulfonium trifluoromethanesulfonate B-2: Triphenylsulfonium nonafluoro-n-butanesulfonate B-3: Triphenylsulfonium 2- (bicyclo [2.2.1] heptan-2-yl) -1 , 1,2,2-Tetrafluoroethanesulfonate B-4: Triphenylsulfonium 10-camphorsulfonate
solvent
PGMEA: Propylene glycol monomethyl ether acetate MAK: 2-heptanone EL: Ethyl lactate FAL: 2,2,3,3,4,4,5,5-octafluoro-1-pentanol

Claims (4)

It has a repeating unit represented by the following general formula (I), and is a ratio (%) of [—OR group where R is a monovalent acid-dissociable group] to [total amount of —OR groups in the polymer]. A polymer having a polystyrene-reduced weight average molecular weight of 500 to 1,000,000 by gel permeation chromatography (GPC), wherein the introduction rate of the defined monovalent acid dissociable group is 9.0% or more and 26% or less .

[In General Formula (I), each R is independently a hydrogen atom or a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a 2-methylpropyl group, or a 1-methylpropyl group. , T-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-decyl group, cyclopentyl group, cyclohexyl group, 4-t-butylcyclohexyl group, cycloheptyl group or cyclo Alkyl group consisting of octyl group; methoxycarbonyl group, ethoxycarbonyl group, i-propoxycarbonyl group, i-butylcarbonyl group, t-butoxycarbonyl group, 9-fluorenylmethylcarbonyl group, 2,2,2-trichloroethyl Carbonyl group, 2- (trimethylsilyl) ethylcarbonyl group, vinylcarbonyl group, allylcarbonyl An organic carbonyl group consisting of benzylcarbonyl group, 4-ethoxy-1-naphthylcarbonyl group or methyldithiocarbonyl group; or methoxymethyl group, ethoxymethyl group, 2-fluoroethoxymethyl group, t-butoxymethyl group, benzyloxymethyl Group, 2-methoxyethoxymethyl group, trimethylsiloxymethyl group, triethylsiloxymethyl group, 1-ethoxyethyl group or 1-methyl-1-methoxyethyl group, together with an oxygen atom to which R is bonded, an acetal group or a ketal 1 represents a monovalent acid dissociable group selected from the group of organic groups forming the group. ] The polymer according to claim 1, wherein the monovalent acid-dissociable group for R is selected from the group consisting of a methoxymethyl group, an ethoxymethyl group, a 2-fluoroethoxymethyl group, and a t-butoxymethyl group. (A) Among the polymers according to claim 1 or claim 2 , an alkali-insoluble or hardly alkali-soluble polymer that becomes readily alkali-soluble when the acid-dissociable group is dissociated, and (B) A radiation-sensitive resin composition comprising a radiation-sensitive acid generator. (B) The radiation-sensitive acid generator is triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium 2- (bicyclo [2.2.1] heptan-2-yl) -1,1,2,2 The radiation sensitive resin composition of Claim 3 containing at least 1 sort (s) chosen from the group of -tetrafluoroethane sulfonate or triphenylsulfonium 10-camphor sulfonate.