KR20170026140A - Process for forming resist pattern and chemically amplified radiation-sensitive resin composition - Google Patents

Abstract

The present invention relates to a method for forming a resist pattern, which allows formation of a resist pattern having high sensitivity, small edge roughness and high resolution. The method according to the present invention comprises the steps of: forming a resist film on a substrate by using a chemically amplified radiation-sensitive resin composition which comprises a first component whose solubility to a developing solution is varied with the action of an acid, a second component generating an acid by the action of the first exposure light including radiation with a first wavelength, and a sensitizer precursor converted into a sensitizer by the action of the first exposure light; a first exposure step in which the resist film is exposed with the first exposure light; a second exposure step in which the resist film is exposed with the second exposure light including radiation with a second wavelength longer than the first wavelength; and developing the resist film exposed with the second exposure light by using a developing solution containing an organic solvent as a main ingredient. In the method, when the absorptivity of the sensitizer precursor at the second wavelength is (IPP) and that of the sensitizer at the second wavelength is (IP), the value of (IPP)/(IP) is 0.2 or less.

Description

TECHNICAL FIELD [0001] The present invention relates to a resist pattern forming method and a chemical amplification type radiation sensitive resin composition,

The present invention relates to a resist pattern forming method and a chemically amplified radiation-sensitive resin composition.

In the exposure process of a semiconductor device, a finer pattern is required with the increase in the circuit integration and the higher speed. For example, extreme ultraviolet (EUV, wavelength: 13.5 nm) has been actively developed as a promising technique for the production of next-generation semiconductor devices. However, it is difficult to develop a light source device having a high output power (100W) required for mass production application. In the present situation, it remains at a level of 10W, and exposure takes time to form a pattern latent image. Further, in the direct electron beam drawing method using the electron beam EB, a fine pattern can be formed with a high precision with a small beam diameter. However, it takes a long time to draw a pattern as the pattern becomes complicated. As described above, in the exposure technique using EUV or electron beam, a fine pattern can be formed, but the throughput is low.

In order to solve this problem, the sensitivity of the resist material has been increased to reduce the exposure time as much as possible. For example, in the resist composition disclosed in Patent Document 1, sensitivity and resolution are improved by a composition containing specific resins and compounds.

Japanese Patent Application Laid-Open No. 2002-174894

However, there is a trade-off relationship between sensitivity, resolution and three important performances of a resist called nano edge roughness (LER), and when the sensitivity of the resist is increased, the resolution and the LER decrease. As a result, there is a limit to making the resist high resolution and high sensitivity without lowering the LER, and the problem that the throughput is low can not be sufficiently solved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to provide a resist pattern forming method capable of improving the sensitivity of a resist by solving the trade-off relationship and capable of forming a resist pattern with a small LER, And a chemically amplified radiation-sensitive resin composition used in the resist pattern forming method.

The method for forming a resist pattern according to the present invention is a method for forming a resist pattern, which comprises: a first component (hereinafter also referred to as a "component (A)") whose solubility in a developer changes by the action of an acid (Hereinafter also referred to as a "component [B]") that generates an acid by the action of a first exposure light (hereinafter also referred to as "exposure light (I)") Sensitive radiation sensitive resin composition containing a sensitizer precursor (hereinafter also referred to as " [C] sensitizer precursor ") changing to a sensitizer by the action of the light (I) (Hereinafter also referred to as " resist film forming step "), a step of forming a resist film on the substrate (hereinafter also referred to as " resist film forming step " (Hereinafter also referred to as " wavelength (II) ") longer than wavelength (I) (Hereinafter, also referred to as " exposure step (hereinafter also referred to as " exposure step ") in which a resist film exposed with exposure light I is exposed with a second exposure light (Hereinafter also referred to as a " developing step ") of developing a resist film exposed with the exposure light (II) with a developing solution containing an organic solvent as a main component (I ^PP ) of the [C] sensitizer precursor at the wavelength (II) and the absorbance at the wavelength (II) of the sensitizer is defined as I ^P , ^PP ) / (I ^P ) is 0.2 or less.

The chemically amplified radiation-sensitive resin composition of the present invention is a chemically amplified radiation-sensitive resin composition for use in the method for forming a resist pattern according to the present invention, which comprises a component [A] Component [B] which generates an acid by the action of the exposure light (I) containing radiation of the exposure light (I) and a sensitizer precursor which changes into a sensitizer by the action of the exposure light (I).

According to the resist pattern forming method and the chemically amplified radiation sensitive resin composition of the present invention, a resist pattern with high sensitivity, small nano-edge roughness, and high resolution can be formed.

1 (a) to 1 (e) are schematic diagrams showing the steps of the resist pattern forming method of the present embodiment.
2 is a diagram showing the energy irradiation amount-residual film ratio curve in the resist pattern forming method of the present embodiment.
3 is a diagram showing the energy irradiation amount-time curve in the resist pattern forming method of the present embodiment.
4 (a) to 4 (d) are views for explaining the steps of a resist pattern forming method according to a further embodiment of the present invention.
5 (a) to 5 (c) are diagrams for explaining Example 1 of the resist pattern forming method of the present invention.
6A to 6D are diagrams for explaining a second specific example of the resist pattern forming method of the present invention.
7 is a chemical reaction formula in this embodiment.
Fig. 8 is a graph showing absorption rates of DOMeBzH and DOMeBzO.
Fig. 9 is a schematic diagram showing changes in concentration of an acid, a sensitizer and a quencher in this embodiment, wherein (a) shows the concentration immediately after irradiation of the exposure light I, (b) (C) shows the concentration after the exposure light (II) is irradiated.
10 is a schematic plan view when the line pattern is viewed from above.
11 is a schematic sectional view on the line pattern.

Hereinafter, a method of forming a resist pattern and an embodiment of the radiation-sensitive resin composition (I) according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments.

A method of forming a resist pattern according to an embodiment of the present invention will be described with reference to Figs. 1 to 3. Fig. 1 is a schematic diagram showing a step of the resist pattern forming method of the present embodiment. 2 is a diagram showing the energy irradiation amount-residual film ratio curve in the resist pattern forming method of the present embodiment. 3 is a diagram showing the energy irradiation amount-time curve in the resist pattern forming method of the present embodiment. The resist pattern forming method of the present embodiment is executed by steps S101 to S110.

≪ Resist film forming step &

First, as shown in Fig. 1A, a resist film 12 is formed on a substrate 11 in a resist film forming step (S101). Specifically, a resist pattern 12 is formed by preparing a substrate 11 (for example, a wafer), applying a chemically amplified radiation-sensitive resin composition (I) onto the substrate 11, do. The radiation sensitive resin composition (I) will be described later. The present invention uses a developer containing an organic solvent as a main component as the developer (I) in a development process to be described later, so that the exposed portion becomes insoluble or hardly soluble in the developer (I), and the unexposed portion is dissolved in the developer Therefore, a negative type resist pattern is formed.

The resist film may be formed, for example, by laminating the radiation sensitive resin composition (I) directly on a substrate, that is, on a substrate, or on a below-mentioned organic undercoat film or a silicon- And a method of pre-baking the coating film. Examples of the application method of the radiation-sensitive resin composition (I) include a spin coating method, a roll coating method, a dipping method and the like. The temperature and time for prebaking are not particularly limited and may be arbitrarily set so that the solvent contained in the radiation-sensitive resin composition (I) can be removed.

2, when the amount of energy irradiated on the resist film exceeds the threshold value Ea (hereinafter also referred to as " latent image forming energy "), a latent image is formed on the resist film, It becomes weak. If the amount of energy further increases to exceed the threshold value Et (hereinafter also referred to as " required energy amount "), the portion where the latent image is formed becomes insoluble or weak in developer (I).

<Organic Undercoat Layer Forming Step>

A step of forming an organic underlayer film on the surface of the substrate on which the resist film is to be formed may be provided before the resist film forming process.

Examples of the organic undercoat film include an organic film formed by using, for example, a composition for a resist underlayer film, and a carbon film formed by a conventionally known CVD (Chemical Vapor Deposition) method.

&Lt; Silicon-containing film forming step &

The method may further include a step of forming a silicon-containing film on the surface of the organic underlying film on which the resist film is to be formed, between the organic underlying film forming step and the resist film forming step.

The silicon-containing film is formed using, for example, a polysiloxane composition containing a polysiloxane and a solvent. The polysiloxane is not particularly limited as long as it is a polymer having a siloxane bond.

Examples of the method for forming the silicon-containing film include a method in which the polysiloxane composition is applied to the surface of the organic undercoat film on which the resist film is to be formed to form a coating film and the coating film is cured by heat treatment and / .

&Lt; Protective film forming step &

A step of forming a protective film on the surface side of the resist film opposite to the substrate by a composition for forming a protective film between the resist film forming step and the exposure step (1) described below.

By the formation of the protective film, it is possible to prevent the immersion liquid from directly contacting the resist film in the case of performing liquid immersion lithography and to prevent degradation of the resist performance due to penetration of the immersion liquid into the resist film and elution of the resist film component into the immersion liquid And the contamination of the lens of the exposure apparatus by the eluted component into the immersion liquid can be prevented. In addition, since the emission of outgas from the resist film during exposure using radiation such as EUV or electron beam can be reduced, contamination of the exposure apparatus can be prevented.

The composition for forming a protective film contains a polymer and a solvent. As the polymer, a polymer having a fluorine atom and / or a silicon atom is preferable. Since the protective film containing such a polymer has better solubility in the developer (I) containing an organic solvent as a main component, the dissolution residue and the like of the protective film can be suppressed. Examples of the polymer having a fluorine atom and / or a silicon atom include polymers similar to those exemplified as the [F] polymer of the radiation-sensitive resin composition (I) described later.

As the solvent contained in the composition for forming a protective film, it is preferable not to dissolve the resist film from the viewpoint of dissolving the resist film and forming a good resist pattern, and a solvent different from the later-described developer (I) is more preferable. Examples of such a solvent include an alcohol-based solvent, a fluorine-based solvent, and a hydrocarbon-based solvent. Of these, alcoholic solvents containing no fluorine atom are preferred.

As a method of forming the protective film, for example, a method of applying a composition for forming a protective film onto a resist film to form a coating film, and then pre-baking the coating film can be given.

&Lt; Exposure step (1) >

1 (b), the resist film 12 is exposed by the irradiation of the exposure light I in the exposure step (1) (S103). An acid is generated from the [B] component in the resist film 12 by irradiation of the exposure light I, and a sensitizer is generated from the [C] sensitizer precursor. Both the generation of an acid from the component [B] and the formation of a sensitizer from the [C] sensitizer precursor occur in the resist film 12. By the action of the acid generated from the component [B], polarity conversion, crosslinking, decomposition reaction, etc. occur in the component [A]. As a result, the solubility of the component [A] in the developer changes. In order to form a resist pattern by development, it is necessary to generate a certain amount of acid from the component [B].

The exposure step (1) is performed in, for example, a vacuum or an inert atmosphere. The exposure light I is emitted from the exposure light source 21 so as to irradiate the resist film 12 from above. Here, the exposure light (I) is irradiated on one surface in the resist film (12). As shown in Fig. 1, the exposure light I is irradiated on the entire surface in the resist film 12, for example. However, the exposure light I may be irradiated only on a part of the whole of the resist film 12, such as a pattern. The exposure light I is an electromagnetic wave such as visible light, UV (ultraviolet), DUV (deep ultraviolet), EUV, X-ray. Further, the exposure light I may be an electron beam or an ion beam. As the exposure light (I), EUV and electron beams are preferable.

As shown in Fig. 2, in the exposure step (1) (S103), the irradiation dose Ef of the exposure light I is an irradiation dose not exceeding the latent image forming energy amount Ea. That is, in the exposure step (1) (S103), an acid smaller than that required for forming a resist pattern at the time of development is generated from the component [B]. For this reason, in the step of performing the exposure step (1) (S103), the resist film 12 in the developer is not insolubilized or hardened, and a resist pattern is not formed.

<Holding Process>

A step of holding the state of the resist film 12 in the holding step (S105) may be provided after the exposure step (1) as shown in Fig. 1 (c). Specifically, a resist film (a resist film) (not shown) is formed by irradiating the exposure light (I) in the exposure step (1) (S103) while controlling the environment without performing prebaking until the exposure step (2) The amount of the acid generated from the [B] component in the [C] reducing agent precursor and the amount of the reducing agent generated from the [C] reducing agent precursor are suppressed.

For example, the environment around the resist film 12 is an atmosphere capable of controlling the reduction of the amounts of the acid and the sensitizer produced in the exposure step (1). The atmosphere capable of controlling the decrease of the amount of the acid and the sensitizer may be an inert gas atmosphere or a vacuum atmosphere not containing a basic substance. In addition, a protective film for blocking the basic substance and / or oxygen may be formed. In the case of an inert gas atmosphere, for example, nitrogen gas, helium gas, argon gas, or the like is used as the inert gas, and it can be used under reduced pressure and pressure. In the case of a vacuum atmosphere, the periphery of the resist film 12 is evacuated. Preferably, the periphery of the resist film 12 is set to a vacuum of 1 Pa or less. A decrease in the amount of the sensitizer produced in the resist film 12 is suppressed in an atmosphere of an inert gas atmosphere or a vacuum atmosphere.

The environment around the resist film 12 may be an atmosphere or a liquid that can increase the amount of the acid and / or the sensitizer in the resist film 12. An atmosphere of an active gas is used as an atmosphere capable of increasing the amount of the acid and / or the sensitizer. As the active gas atmosphere, for example, a reactive gas for absorbing wavelength shift is used. As the active liquid which can increase the amount of the acid and the sensitizer, for example, a reactive liquid for the absorption wavelength shift is used. The sensitizer produced in the resist film 12 reacts with the active gas or the active liquid and is converted into the active material alpha or the stabilizing material alpha 1 in the exposure step (2) (S107) described later. The active substance? Or the stabilizing substance? 1 can function as a sensitizer in the same manner as the sensitizer produced from the [C] sensitizer precursor. The active substance? Is, for example, an aromatic compound radical or an iodide compound radical, and the stabilizing substance? 1 is, for example, an aromatic compound or an iodine compound. When the active liquid is used, the active liquid may be removed from the resist film 12 before the exposure step (2) (S107) is executed, or the exposure step (2) (S107) may be performed without removing the active liquid It can also be executed.

As a control method of the environment, a method of controlling the temperature of the resist film 12 may also be used. When the temperature of the resist film 12 exceeds a certain threshold temperature, the amount of the acid and / or the sensitizer decreases, so that the temperature of the resist film 12 is kept at or below the threshold value, / / Reduction of the amount of the sensitizer can be suppressed. For example, after the exposure step (1) (S103), the temperature of the resist film (12) is lowered to the threshold value or lower by performing a quenching process in the holding step (S105). The threshold temperature is, for example, 30 占 폚. It is also possible to carry out the exposure step (1) (S103) at a predetermined temperature or lower and maintain the temperature of the resist film (12) at or below the threshold temperature in the holding step (S105).

Also, when the resist film 12 is irradiated with unexpected radiation, the amount of the acid and / or the sensitizer may be decreased during the time until the exposure step (2) (S107) is executed. Therefore, in the holding step (S105), the resist film 12 is placed in an environment not irradiated with radiation.

Since the amount of the acid and / or the sensitizer decreases with time, by controlling the elapsed time between the exposure step (1) (S103) and the later-described exposure step (2) (S107), the resist film 12 ) Of the acid and / or the sensitizer. The time from the exposure step (1) to the later-described exposure step (2) is preferably within 60 minutes. Further, temperature, roughness, or time may be controlled simultaneously with the control of the environment around the resist film 12. [

&Lt; Exposure step (2) >

After the exposure step (1) (S103) or the holding step (S105), the exposure step (2) (S107) is performed as shown in FIG. In the exposure step (2), the resist film 12 exposed with the exposure light (I) is exposed by the irradiation of the exposure light (II). Specifically, the exposure light (II) contains a wavelength (II) longer than the wavelength (I) and acts on the sensitizer, the active material? And / or the stabilizing substance? 1 produced from the [C] sensitizer precursor, It is the radiation that generates acid from component [B]. At the site of the resist film 12 irradiated with the exposure light (II), the acid from the [B] component is decomposed by the action of the sensitizer produced from the [C] sensitizer precursor and the active substance alpha / Or an acid whose structure differs from that of the acid). The exposure light (II) generates an acid from the [B] component by the action of the sensitizer and the active substance? / The stabilizing substance? 1 and generates an acid from the [B] component in the resist film 12 . In this case, at the site of the resist film 12 irradiated with the exposure light (II), an acid (or an acid different in structure from the acid) is generated from the component [B] A sensitizer is produced from the [C] sensitizer precursor by the action of the substance? 1, and an acid (or an acid different in structure from this acid) is generated from the [B] component. 2, in the exposure step (2) (S107), the irradiation dose Ep of the exposure light II is a dose not exceeding the latent image formation energy amount Ea, and the irradiation dose Ep of the exposure light II The total sum of the irradiation amounts Ef of the exposure light I exceeds the required energy amount Et. In other words, in the exposure step (2) (S107), the amount of acid generated from the [B] component by the action of the sensitizer and the active material? / Stabilizer? 1 is [B The amount of the acid generated from the component [B] in the exposure step (1) (S103) and the amount of the acid generated in the exposure step ( 2) The total amount of the acid obtained from the [B] component in (S107) exceeds the amount required for forming a resist pattern at the time of development.

The exposure light (II) is emitted from the exposure light source 22 (22) so as to irradiate the resist film 12 from above. The exposure light source 2 22 may be the same as the exposure light source 21 for emitting the exposure light I or may be different from the exposure light source 21. Here, the exposure light (II) is irradiated in a patterned manner in the region of the resist film 12 irradiated with the exposure light (I). The exposure light (II) can be selected according to the resolution of the pattern to be formed. For example, the exposure light (II) may be an electronic file such as UV, DUV, EUV or X-ray, or may be an electron beam or an ion beam. The exposure step (2) is performed in, for example, a vacuum atmosphere, an active gas atmosphere, or an inert atmosphere. As described above, the resist film 12 is provided with the exposed portion A 121 irradiated only with the exposure light I and the exposed portion B irradiated with both the exposure light I and the exposure light II 122) (see Fig. 1).

<Development Process>

After the exposure step (2), the developing step (S110) is performed as shown in Fig. 1 (e). In the developing process, the resist film 12 is developed. The development of the resist film 12 is performed by, for example, performing post exposure bake (PEB) and then inserting the substrate 11 into the developer bath. In this embodiment, the irradiation dose Ef of the exposed portion (A) 121 of the resist film 12 does not exceed the latent image forming energy amount Ea. The exposed portion (A) 121 is dissolved in the developing solution since the amount of the acid generated from the [B] component in the exposed portion (A) 121 is smaller than that required for forming the resist pattern. On the other hand, the energy amount Es (that is, Ef + Ep) received by the exposed portion (B) 122 of the resist film 12 exceeds the required energy amount Et. In the exposed part (A) 122, the total amount of the acid generated from the component [B] and the amount of the acid generated by the action of the sensitizer or the like in the exposure step (1) , The exposed portion (B) 122 of the developing solution becomes insoluble or hardly soluble in the developing solution. As described above, a predetermined resist pattern is formed on the substrate 11.

In the developing process, a developer (I) containing an organic solvent as a main component is used. (I) containing an organic solvent as a main component makes it possible to obtain a high-resolution image by forming a pattern having a small exposure area, such as a trench pattern or a hole pattern, in comparison with a case of forming a positive image using an alkali- It is possible to form a pattern of a pattern. In the case of forming a positive-tone image using an alkali water-soluble developer, since the exposed portion is narrow, the optical contrast is insufficient and there is a limit to the miniaturization of the pattern. On the other hand, in the case of developing using a developer (I) containing an organic solvent as a main component, it is possible to form a pattern of high resolution because a pattern exposure is performed with an area sufficient to take an optical contrast of the exposed portion. Means that the organic solvent in the developer (I) is usually at least 50 mass%, preferably at least 70 mass%, more preferably at least 90 mass%, particularly preferably at least 95 mass% . Examples of components other than the organic solvent in the developing solution (I) include water and silicone oil.

Examples of the organic solvent include an alcohol solvent, an ether solvent, a ketone solvent, an amide solvent, an ester solvent, a hydrocarbon solvent and the like.

As the alcoholic solvent, for example,

Propanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, Butanol, 2-ethylhexanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol , sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, secundecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, Monoalcohol solvents such as furyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol and diacetone alcohol;

Propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4- Polyhydric alcohol solvents such as 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol and tripropylene glycol;

Ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol mono Methyl ethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene Glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and dipropylene glycol monopropyl ether; and the like.

As the ether-based solvent, for example,

Dialkyl ether solvents such as diethyl ether, dipropyl ether and dibutyl ether;

Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;

Containing ether solvents such as diphenyl ether and anisole, and the like.

As the ketone-based solvent, for example,

Butyl ketone, methyl n-butyl ketone, di-tert-butyl ketone, methyl n-butyl ketone, methyl n-butyl ketone, methyl n-hexyl ketone, iso-butyl ketone, trimethylnonanone and the like:

Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, and methylcyclohexanone;

2,4-pentanedione, acetonyl acetone, acetophenone, and the like.

As the amide-based solvent, for example,

Cyclic amide solvents such as N, N'-dimethylimidazolidinone and N-methylpyrrolidone; A chain amide type such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, Solvents, and the like.

As the ester-based solvent, for example,

Propyl acetate, isopropyl acetate, n-butyl acetate, 3-methylbutyl acetate, 2-butyl acetate, n-pentyl acetate, i-pentyl acetate, sec- Acetic acid ester solvents such as methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate and n-nonyl acetate;

Ethylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, Polyhydric alcohol partial ether acetate type solvents such as monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate and dipropylene glycol monoethyl ether acetate;

lactone solvents such as? -butyrolactone and? -valerolactone;

Carbonate-based solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate and propylene carbonate;

Hydroxy acid esters such as methyl lactate, ethyl lactate, n-butyl lactate, and methyl n-amyl glycol lactate;

Dicarboxylic acid diesters such as diethyl oxalate, di-n-butyl oxalate, diethyl malonate, dimethyl phthalate and diethyl phthalate;

Diacetic acid glycol, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, isoamyl propionate, methyl acetoacetate, and ethyl acetoacetate.

As the hydrocarbon-based solvent, for example,

aliphatic alcohols such as n-pentane, iso-pentane, n-hexane, isohexane, n-heptane, isoheptane, 2,2,4-trimethylpentane, n-octane, iso-octane, cyclohexane and methylcyclohexane Hydrocarbon solvents;

Benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, isopropylbenzene, diethylbenzene, isobutylbenzene, triethylbenzene, di- And aromatic hydrocarbon solvents such as amylnaphthalene.

Among them, an alcohol solvent, an ether solvent, a ketone solvent, an amide solvent and an ester solvent are preferable and a monoalcohol solvent, a polyhydric alcohol partial ether solvent, an aromatic ring ether solvent, a chain ketone solvent, Ketone solvents, chain amide solvents, acetic acid ester solvents, lactone solvents and hydroxy acid esters are more preferable, and ethanol, 2-propanol, dibutyl ether, anisole, methyl amyl ketone, cyclohexanone, N, N-dimethylacetamide, 3-methylbutyl acetate, n-butyl acetate,? -Butyrolactone and ethyl lactate are more preferable. The developer (I) may contain one or more organic solvents.

The developer (I) may contain, in addition to the organic solvent, a first compound (hereinafter, referred to as &quot; the first compound &quot;) that forms ionic bonds, hydrogen bonds, covalent bonds, coordination bonds, dipole interactions, M] compound ").

Examples of the [M] compound include a nitrogen-containing compound, an onium salt, a polymer having an onium salt, a basic polymer, and a phosphorus compound. Each compound will be described below.

(Nitrogen-containing compound)

The nitrogen-containing compound is a compound containing at least one nitrogen atom. The nitrogen-containing compound can form a hydrogen bond, a covalent bond and / or a dipole interaction with a polar group such as -COOH generated in the [A] polymer.

The number of nitrogen atoms contained in the nitrogen-containing compound may be 1 or may be 2 or more.

The lower limit of the molecular weight of the nitrogen-containing compound is preferably 50, more preferably 100. The upper limit of the molecular weight is preferably 900, more preferably 700.

Examples of the nitrogen-containing compound include compounds represented by the following formula (A).

In the formula (A), R ^X is a single bond or an n-valent organic group. R ^Y is a single bond, a substituted or unsubstituted methylene group, an alkylene group, an alkenylene group, an alkynylene group, a cycloalkylene group or a monovalent aromatic group. Each R ^z independently represents a hydrogen atom or an alkyl group. n is an integer of 1 to 8; When n is 2 or more, a plurality of R ^Y may be the same or different. Provided that R ^X and R ^Y are not both a single bond.

Examples of the n-valent organic group represented by R ^X include a carbon atom, a nitrogen atom, -NH-, -NR-, -O-, -S-, a carbonyl group, an alkylene group, an alkenylene group, An alkylene group, an aromatic group, a heterocyclic group, a group in which two or more of these are combined, and a group in which some or all of the hydrogen atoms of these groups are substituted with a substituent. R is a monovalent organic group, preferably an alkyl group, an alkylcarbonyl group, or an alkylsulfonyl group. As R ^X , an alkyl group, a nitrogen atom, -NH- and -NR- are preferable. Examples of the substituent of these groups include alkyl groups, alkoxy groups, alkylcarbonyl groups, alkylcarbonyloxy groups, alkyloxycarbonyl groups, alkenyl groups, alkenyloxy groups, alkenylcarbonyl groups, alkenylcarbonyloxy groups, alkenyloxycarbonyl groups, alkynyl groups, An aralkyloxycarbonyl group, a hydroxy group, an amide group, an alkoxycarbonyl group, an alkynyloxycarbonyl group, an alkynyloxycarbonyl group, an aralkyloxycarbonyl group, an aralkyloxy group, an aralkylcarbonyl group, an aralkylcarbonyloxy group, A carboxyl group, a cyano group, and a fluorine atom.

The number of carbon atoms of the alkylene group represented by R ^Y is preferably 2 to 40, more preferably 2 to 20, and even more preferably 2 to 12. The number of carbon atoms of the alkenylene group and the alkynylene group represented by R ^Y is preferably 2 to 40, more preferably 2 to 20, and even more preferably 2 to 12. The number of carbon atoms of the cycloalkylene group represented by R ^Y is preferably 3 to 40, more preferably 3 to 20, and still more preferably 5 to 12. The monovalent aromatic group represented by R ^Y includes a non-benzene aromatic ring and may be a hydrocarbon such as benzene, pyrrole, furan, thiophene, indole, naphthalene, anthracene, tetracene, benzofuran, benzothiophene, And groups obtained by removing one hydrogen atom from an aromatic heterocyclic compound.

n is preferably 1 to 6, more preferably 1 to 4, and even more preferably 1 to 3.

Examples of the nitrogen-containing compound include compounds in which n is 1, examples of which include tripentylamine, trioctylamine, and the like; compounds in which n is 2 include N, N, N ', N'-tetramethylethylenediamine, N, N , N ', N'-tetramethyltrimethylenediamine and the like, and the compound represented by the following formula, wherein n is 3 or more.

(Onium salt)

Onium salts are compounds containing onium cations and anions. The onium salt can form a hydrogen bond and / or a dipole interaction with a polar group such as -COOH generated in the [A] polymer.

The onium salts include, for example, ammonium salts, phosphonium salts, oxonium salts, sulfonium salts, selenonium salts, carbonium salts, diazonium salts and iodonium salts. The cation included in the onium salt includes those having a positive charge on a hetero atom of a heteroaromatic ring. Examples of such onium salts include pyridinium salts, imidazolium salts and the like.

The onium salt may be a polyionium salt having two or more onium ion atoms in one molecule. As the polyvalent metal salt, a compound in which two or more cations are linked by a covalent bond is preferable. Examples of the polyvalent metal salt include a diazonium salt, an iodonium salt, a sulfonium salt, an ammonium salt, and a phosphonium salt.

The anion contained in the onium salt may be monovalent or polyvalent. Examples of the monovalent anion include a sulfonic acid anion, a formic acid anion, a carboxylic acid anion, a sulfinic acid anion, a boron anion, a halide ion, a phenol anion, an alkoxy anion, and a hydroxide ion. Examples of the divalent anions include oxalic acid ions, phthalic acid ions, maleic acid ions, fumaric acid ions, tartaric acid ions, malic acid ions, lactic acid ions, sulfuric acid ions, diglycolic acid ions, 2,5-furandicarboxylic acid ions, .

Examples of monovalent anions, such as ^{Cl -, Br -, I -} , AlCl 4 -, Al 2 Cl 7 -, BF 4 -, PF 6 -, ClO 4 -, NO 3 -, CH 3 COO -, CF 3 _{^{COO -, CH 3 SO 3 -}} , CF 3 SO 3 -, (CF 3 SO 2) 2 N -, (CF 3 SO 2) 3 C -, AsF 6 -, SbF 6 -, NbF 6 -, TaF 6 - ^{_{, F (HF) n -,}} (CN) 2 N -, C 4 F 9 SO 3 -, (C 2 F 5 SO 2) 2 N -, C 3 F 7 COO -, (CF 3 SO 2) (CF _{^{3 CO) N -, C 9}} H 19 COO -, (CH 3) 2 PO 4 -, (C 2 H 5) 2 PO 4 -, C 2 H 5 OSO 3 -, C 6 H 13 OSO 3 -, C ^{_{8 H 17 OSO 3 -, CH}} 3 (OC 2 H4) 2 OSO 3 -, C 6 H 4 (CH 3) SO 3 -, (C 2 F 5) 3 PF 3 -, CH 3 CH (OH) COO - _{, B (C 6 F 5)} 4 -, FSO 3 -, C 6 H 5 O -, (CF 3) 2 CHO -, (CF 3) 3 CHO -, C 6 H 3 (CH 3) 2 O -, C ₂ H ₅ OC ₆ H ₄ COO ^- and the like.

The onium cation included in the onium salt includes, for example, a cation represented by the following formula.

Examples of anions included in the onium salt include anions represented by the following formulas.

As the onium salt, for example, a compound represented by the following formula can be given.

The lower limit of the pKa of the conjugate acid of the anion contained in the onium salt is preferably 4.0, more preferably 5.0. The upper limit of the pKa is preferably 11.0, more preferably 10.5. By setting the pKa of the conjugate acid of the anion in the above range, it is possible to further suppress the patterning of the resist pattern. The pKa is a calculated value obtained by ACD / ChemSketch (ACD / Labs 8.00 Release Product Version: 8.08).

Hereinafter, the value of the pKa of the conjugate acid of the anion is shown.

The lower limit of the ratio of the sum of the atomic weights of the total carbon atoms (the total number of carbon atoms x 12 / the sum of the atomic weights of all the atoms constituting the cation) to the sum of the atomic weights of the total atoms constituting the cation of the onium salt is preferably 0.4, 0.5 is more preferable. The upper limit of the ratio is preferably 0.75, more preferably 0.65.

As the onium salt, a compound represented by the following formula (B-1) and a compound represented by the following formula (B-2) are preferable.

In the formulas (B-1) and (B-2), M ⁺ is, independently of each other, a nitrogen cation, a phosphorous cation, a sulfur cation or an iodine cation. Each R ^C independently represents a hydrogen atom or a monovalent organic group. m1 is an integer of 2 to 4; When M ⁺ is a nitrogen cation or a phosphorous cation, m2 is 3. When M is a sulfur cation, m2 is 2. When M ⁺ is an iodine cation, m2 is 1. When there are a plurality of R ^c , a plurality of R ^c may be the same or different and may be combined with each other to form a ring structure together with M ^{+ to} which they are bonded. L ^A is a divalent linking group. Y ^- are each independently a monovalent anion.

As M ^&lt; ^{+ &gt;} , a nitrogen cation is preferable.

Examples of the monovalent organic group represented by R ^C include a monovalent hydrocarbon group, a group containing a heteroatom-containing group between the carbon-carbon atoms of the hydrocarbon group, a part of hydrogen atoms having a group containing the hydrocarbon group and the heteroatom-containing group, And a group in which all of them are substituted with a substituent.

Examples of the hydrocarbon group include a chain hydrocarbon group such as an alkyl group, an alkenyl group and an alkynyl group; Alicyclic hydrocarbon groups such as a cycloalkyl group and a cycloalkenyl group; An aryl group, and an aromatic hydrocarbon group such as an aralkyl group. The number of carbon atoms of the chain hydrocarbon group is preferably from 1 to 20, more preferably from 1 to 15, and still more preferably from 1 to 5. The carbon number of the alicyclic hydrocarbon group is preferably from 3 to 20, more preferably from 5 to 15. The aromatic hydrocarbon group is preferably 6 to 20, more preferably 6 to 10.

Examples of the hetero atom of the hetero atom-containing group include a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a selenium atom, and a tellurium atom. As the group containing a hetero atom, such as ^{_{-Y 1 -, -N (R a}} ) -, -C (= Y 2) -, -CON (R b) -, -C (= Y 3) Y 4 -, -SO _{2 t} -, -SO ₂ N (R ^c ) -, a halogen atom, or a combination of two or more of these groups. Y ₁ to Y ₄ each independently represent an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom, and among these, an oxygen atom and a sulfur atom are preferable from the viewpoint of easier handling. R ^a , R ^b , and R ^c are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. t is an integer of 1 to 3; When a heteroatom-containing group is contained between carbon-carbon atoms of an aromatic hydrocarbon group, an aromatic heterocyclic group is constituted.

As R ^C , a group containing an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and a heteroatom-containing group between carbon-carbon of these groups is preferable.

Examples of the cation of the onium salt include a pyridinium cation represented by the following formula (C-1) and the like when the ring structure formed by combining a plurality of R ^c has aromaticity. When R ^C further includes a hetero atom, examples of the cation of the onium salt include imidazolium cations represented by the following formula (C-2).

In the formulas (C-1) and (C-2), R ^V is, independently of each other, a hydrogen atom or an alkyl group. The plurality of R &lt; ^V &gt; may bond together to form a ring together with the carbon chain to which they are bonded. R ^C is synonymous with the above formula (B-1).

As the divalent linking group represented by L ^A , a substituted or unsubstituted divalent hydrocarbon group, -O-, -S-, -SO ₂ -, -NR-, -CO-, -NH-, -COO-, CONH-, or a combination of two or more of these groups. R is an alkyl group. Of these, substituted or unsubstituted divalent hydrocarbon groups are preferable, and substituted or unsubstituted divalent straight chain hydrocarbon groups of 1 to 8 carbon atoms, substituted or unsubstituted alicyclic hydrocarbon groups of 3 to 10 carbon atoms, and substituted or unsubstituted More preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms, and still more preferably a methylene group, an ethylene group, a propylene group and a phenylene group.

(A polymer having an onium salt)

A polymer having an onium salt is a polymer having an onium salt structure in a side chain or a main chain. The polymer having an onium salt can form a hydrogen bond and / or a dipole interaction with a polar group such as -COOH generated in the [A] polymer. The definition of the onium salt is the same as that of the onium salt described above. Examples of the polymer having an onium salt include a polymer having a structural unit containing an onium salt structure, and the like.

Examples of the polymer having an onium salt include a polymer having a structural unit represented by the following formula (D-1).

In the formula (D-1), R ^p is a hydrogen atom or an alkyl group. L ^p is a divalent linking group. A ^p is a group in which one hydrogen atom is removed from an onium salt represented by any one of the formulas (B-1) and (B-2).

The number of carbon atoms of the alkyl group represented by R ^p is preferably from 1 to 20, more preferably from 1 to 10.

The bivalent linking group represented by L ^p includes, for example, groups similar to those exemplified as the bivalent linking group of L ^A above. Among them, an alkylene group, an arylene group, -COO-, and a combination of two or more of them are preferable, and an alkylene group is more preferable.

The lower limit of the content ratio of the structural unit represented by the formula (D-1) to the total structural unit constituting the polymer having the onium salt-containing structural unit is preferably 30 mol%, more preferably 50 mol% Do. The upper limit of the content is preferably 100 mol%, more preferably 90 mol%.

The lower limit of the Mw of the polymer having an onium salt is preferably 1,000, more preferably 2,000. The upper limit of the Mw is preferably 30,000, more preferably 10,000.

As the structural unit represented by the above formula (D-1), a structural unit represented by the following formula (D-2) is preferable.

In the formula (D-2), each R ^C independently represents a hydrogen atom or a monovalent organic group. R ^p , L ^p and Y ^- are as defined in the above formulas (D-1), (B-1) and (B-2).

As the structural unit represented by the above formula (D-2), structural units represented by the following formulas (D-3) to (D-5) are preferable.

R ^C , R ^p and Y ^- in the formulas (D-3) to (D-5) are the same as those in formula (D-2).

L ^B in the formula (D-4) is -O-, -NH- or -NR-. L ^C is an alkylene group.

(Basic polymer)

The basic polymer is a polymer having a proton-accepting group. The basic polymer can form a hydrogen bond, a covalent bond, a coordination bond and / or a dipole interaction with a polar group generated in the polymer [A] described later by the proton-accepting group. The proton-accepting group may be contained anywhere in the main chain and the side chain of the basic polymer.

The basic polymer is usually a polymer having a structural unit containing a proton-accepting group, but may further have a structural unit not containing a proton-accepting group.

Examples of the proton accepting group include an amino group and a phosphino group. The "amino group" is a concept including a primary amino group, a secondary amino group and a tertiary amino group. The secondary amino group also includes cyclic secondary amino groups such as pyrrolidino group, piperidino group, piperazino group, and hexahydrotriazino group. The term "phosphino group" is a concept including a primary phosphino group, a secondary phosphino group and a tertiary phosphino group. As the proton accepting group, an amino group is preferable.

Examples of the side chain containing an amino group include a structure represented by the following formula.

In the above formula, * indicates a site bonding with the main chain of the basic polymer.

Examples of the basic polymer having an amino group include, for example, polyarylamine, polyethyleneimine, polyvinylpyridine, polyvinylimidazole, polypyrimidine, polytriazole, polyquinoline, polyindole, polypyrrole, polyvinylpyrrolidone , Polybenzimidazole, and the like.

Examples of the structural unit containing a proton-accepting group include a structural unit represented by the following formula (E).

In the formula (E), R ^q is a hydrogen atom or an alkyl group. R ^D and R ^E are each independently a hydrogen atom or a monovalent organic group. L ^q is a divalent linking group.

The number of carbon atoms of the alkyl group represented by R ^q is preferably 1 to 4, more preferably 1 and 2.

Examples of the monovalent organic group represented by R ^D and R ^E include groups similar to those exemplified as the organic group of R ^C.

Examples of the divalent linking group represented by L ^q include groups similar to those exemplified as the divalent linking group of L ^A above. Among them, an alkylene group, an arylene group, -COO-, and a combination of two or more of them are preferable, and an alkylene group is more preferable.

Examples of the structural unit represented by the formula (E) include a structural unit represented by the following formula.

The lower limit of the content of the structural unit represented by the formula (E) to the total structural units constituting the polymer having the structural unit containing a proton-accepting group is preferably 40 mol%, more preferably 70 mol%. The upper limit of the content is preferably 100 mol%, more preferably 90 mol%.

The lower limit of the Mw of the basic polymer is preferably 1,000, more preferably 2,000. The upper limit of the Mw is preferably 30,000, more preferably 10,000.

(Phosphorus compound)

A phosphorus compound is a compound containing at least one trivalent phosphorus atom. The lower limit of the molecular weight of the phosphorus compound is preferably 70, more preferably 100. The upper limit of the molecular weight is preferably 500, more preferably 300.

As the phosphorus compound, a compound represented by the following formula (F-1) and a compound represented by the following formula (F-2) are preferable.

In the formulas (F-1) and (F-2), R ^W is, independently of each other, a monovalent organic group. L ^W is a divalent linking group.

The monovalent organic group represented by R ^W includes, for example, groups similar to those exemplified as the organic group of R ^C.

Examples of the bivalent linking group represented by L ^W include the same groups as exemplified as the bivalent linking group of L ^A above. Of these, bivalent hydrocarbon groups are preferred.

As the phosphorus compound, for example, a compound represented by the following formula can be given.

The resist pattern forming method of this embodiment has been described with reference to Figs. 1 and 2. Fig. In the present embodiment, before the pattern latent image is formed by irradiating the exposure light II, an acid is generated from the [B] component in the resist film 12 by irradiation of the exposure light I. The amount of the acid generated from the component [B] in the exposure step (2) can be reduced, so that the irradiation time of the exposure light (II) can be shortened, It can be used as a light source. For example, in the case where EUV is used as the exposure light (II) and EUV is irradiated in a pattern on the resist film 12 to form a pattern latent image, according to the present embodiment, the irradiation time of EUV can be shortened A high throughput can be obtained even by using a low-power light source. Thus, according to the present embodiment, the trade-off relationship can be solved, and the sensitivity of the resist film 12 can be improved while maintaining the pattern resolution. Further, the improvement in the throughput of the exposure process is realized, and the expense of the exposure system is drastically reduced. Further, since a light source with a low output power can be applied, the life span of consumable parts in the light source apparatus and the exposure apparatus becomes long, and the maintenance and operation cost can be greatly reduced.

In the present embodiment, a holding step for suppressing reduction in the amount of the acid and / or the sensitizer in the resist film 12 may be executed between the exposure step (1) and the exposure step (2). When the reduction of the amount of the acid and / or the sensitizer is not suppressed, the amount of the acid and / or the sensitizer in the resist film 12 decreases over time after the exposure step (1). For this reason, in the exposure step (2), it is necessary to supply again the energy for generating a reduced amount of acid and / or a sensitizer to the resist film. On the other hand, in the present embodiment, since the reduction of the amount of the acid and / or the sensitizer in the resist film 12 is suppressed, the amount of the acid and / or the sensitizer in the resist film 12 is maintained And the amount of energy to be supplied to the resist film 12 in the exposure step (2) is relatively small. As a result, the sensitivity of the resist film 12 is improved, the exposure time is shortened, and the throughput of the exposure process can be further improved.

In this embodiment, the resist film 12 is irradiated with the exposure light I on one side in the resist film 12 in the exposure step (1) (II), but the present invention is not limited to this. When the total amount of the irradiation amount Ef of the exposure light I and the irradiation amount Ep of the exposure light II exceeds the required amount of energy Et, exposure light (in the form of a pattern) is formed in the resist film 12 in the exposure step (1) I may be irradiated with exposure light (II) over one surface in the resist film 12 in the exposure step (2). In this case, the exposure light I may be selected according to the resolution of the pattern to be formed, and may be an electronic file such as UV, DUV, EUV, X-ray, or an electron beam. The exposure light (II) may be an electronic file such as visible light, UV, DUV, or EUV, or may be an electron beam or an ion beam.

4 is a view for explaining a step of a resist pattern forming method according to a further embodiment of the present invention. Hereinafter, the resist pattern forming method of the present embodiment will be described with reference to FIG. 4, FIG. 1, and FIG. The resist pattern forming method of the present embodiment includes a resist film forming step (S101), an exposure step (1) (S103), an exposure step (2) (S107), and a developing step (S110). Except for that the exposure step (1) is carried out by two irradiation steps and that the exposure step (2) is carried out by one irradiation step, the other steps are the same as the steps And therefore, only the parts required for explanation are shown and explained.

4 (a) and 4 (b), the exposure step (1) includes a pattern exposure step (i) (S103a) and an entire surface exposure step (i) ). As shown in Fig. 4 (a), in the pattern exposure step (i), the resist film 12 is irradiated with exposure light (I) in a pattern. As shown in Fig. 4 (b), in the entire surface exposure step (i), the exposure light I is irradiated to one surface of the resist film 12. The total irradiated amount Ef of the exposure light (I) in the pattern exposure step (i) and the entire surface exposure step (i) is an irradiation dose not exceeding the latent image forming energy amount Ea. As described above, after the exposure step (1) is performed, the resist film 12 is exposed to the exposure part (a) 123 irradiated only once by the exposure light I, (B) 124 of the exposed area.

The holding step (S105) may be executed as shown in Fig. 4 (c) after the exposing step (1) is completed. Subsequently, the exposure step (2) is carried out. As shown in Fig. 4 (d), the exposure step (2) includes a pattern exposure step (ii) (S107a). In the pattern exposure step (ii), the exposure light (II) is irradiated as a pattern in the resist film (12). Specifically, the exposure region (b) 124 of the resist film 12 is irradiated with exposure light (II). The amount of exposure light (II) is such that the sum of the dose Ef of the exposure light (I) and the dose Ep of the exposure light (II) in the exposure part (b) .

In the present embodiment, since the irradiation amount Ef of the exposed portion (a) 123 of the resist film 12 does not exceed the latent image forming energy amount Ea, the exposed portion (a) 123 in the developing process is It is not insoluble or sparingly soluble. On the other hand, since the energy amount Es of the exposed portion (b) 124 of the resist film 12 exceeds the required energy amount Et, the exposed portion (b) 124 in the developing step is insolubilized do. As described above, a predetermined resist pattern is formed on the substrate 11.

In Fig. 4, the exposure step (1) is performed by two irradiation steps, and the exposure step (2) is executed by one irradiation step, but the present invention is not limited to this. The exposure step 1 may be executed by one irradiation step and the exposure step 2 may be executed by two irradiation steps and both the exposure step 1 and the exposure step 2 may be performed by two or more exposure steps . For example, the exposure step (1) may include the entire surface exposure step (i), and the exposure step (2) may include the entire surface exposure step (ii) and the pattern exposure step (ii).

In the case where the exposure step (1) and / or the exposure step (2) are carried out by two irradiation methods, the two irradiation methods may be the same method (either full surface exposure or pattern exposure) It may be an investigation method. In the case of performing by the different irradiation method, either of the whole surface exposure and the pattern exposure may be performed in advance.

In Fig. 4, both the exposure step (1) and the exposure step (2) further include a pattern exposure step, but the present invention is not limited to this. The pattern latent image can be formed on the resist film 12. Either the exposure step (1) or the exposure step (2) may include a pattern exposure step.

Although not shown, the resist pattern forming method of the present invention may further include a process step that is generally executed in the exposure process. For example, it may further include a heat treatment (PEB, for example, pulse heat treatment) step performed after the exposure step (2) or an inversion processing step in which the resist film is reversed between the positive type and the negative type.

Hereinafter, with reference to FIG. 5 and FIG. 6, a method of forming a resist pattern according to this embodiment will be described using specific examples. Fig. 5 is a view for explaining the first specific example of the resist pattern forming method of the present invention, and Fig. 6 is a view for explaining the second specific example of the resist pattern forming method of the present invention. In the following specific examples, the resist film 12 is formed by the chemically amplified radiation sensitive resin composition (I).

[Example 1]

As shown in Fig. 5 (a), the exposure step (1) is executed. In the exposure step (1), the exposure light (I) is irradiated as a pattern. When the exposure step (1) is carried out, an acid is generated from the [B] component in the portion irradiated with the pattern light by the exposure light (I), and a sensitizer is generated from the [C] sensitizer precursor. At this time, since the irradiation amount on the pattern is low, a resist pattern is not formed on the resist film 12 even when the developing process is performed.

Then, as shown in Fig. 5 (b), the holding step may be executed. In the case of performing the holding process, the resist film 12 is placed in an inert gas atmosphere or a vacuum atmosphere environment. The amount of acid generated from the [B] component in the resist film 12 and the amount of the sensitizer produced from the [C] sensitizer precursor are suppressed.

After the holding step, or simultaneously, the exposure step (2) is carried out. In the exposure step (2), the exposure light (II) is irradiated on one surface. As shown in Fig. 5 (b), as the exposure light (II), in the region of the unexposed resist film 12, substantially the acid from the [B] component and the sensitizer from the [C] And the exposure light (II) which is not generated and which activates the sensitizer produced from the [C] sensitizer precursor is appropriately selected. A sensitizer is generated from the [C] sensitizer precursor in the region of the resist film 123 by irradiation of the exposure light (II) and / or the acid (or precursor of an acid or acid, which differs in structure from the [B] ).

Thus, in the exposure step (II), even when the exposure light (II) is irradiated on one surface, an acid is generated only in the first irradiated portion in the pattern image, and activation of the sensitizer generated from the [C] It is caused by one-sided survey only on the part of the survey. As a result, a large amount of acid is generated only in the portion irradiated initially on the pattern, and after the neutralization of the quencher and the acid, which is a base, the acid is generated only in the portion irradiated with the pattern on the initial stage.

Thereafter, a heating process and a developing process are carried out to form a resist pattern as shown in Fig. 5 (c).

[Practical example 2]

As shown in Fig. 6 (a), the exposure step (1) is executed. In the exposure step (1), the exposure light (I) is irradiated as a pattern. When the exposure step (1) is carried out, both the generation of an acid from the component [B] and the formation of a sensitizer from the [C] sensitizer precursor occur in the part irradiated with the pattern light by the exposure light (I). At this time, since the amount of irradiation on the pattern is low, no resist pattern is formed on the resist film 12 even when the development step is performed.

Then, as shown in Fig. 6 (b), the holding step is executed. In the holding step, the resist film 12 is placed in an atmosphere of an active gas atmosphere or an active liquid, and reacted with a sensitizer produced from the [C] sensitizer precursor. The sensitizer is converted into an active substance alpha / stable substance alpha 1 having a high reaction efficiency in the subsequent exposure step (2).

Subsequently, as shown in Fig. 6 (c), the exposure step (2) is carried out in an environment of an active atmosphere or an active liquid. In the exposure step (2), the exposure light (II) is irradiated on one surface. As the exposure light (II), in the region of the unexposed resist film 12, substantially no sensitizer was generated from the [B] component and the [C] sensitizer precursor, and the active substance α / (II) which selectively activates only the exposure light (II). Irradiation of the exposure light (II) causes generation of a sensitizer from the [C] sensitizer precursor and / or formation of an acid or an acid precursor from the [B] component in the resist film 123. The sensitizer reacts with the active atmosphere or the active liquid and is again converted into the active substance alpha / stable substance alpha 1.

Thus, in the exposure step (2), even when the exposure light (II) is irradiated on one surface, an acid is generated only in the first irradiated portion in the pattern image, and the active substance? . As a result, a large amount of acid is generated only in the initial pattern-irradiated portion, and after neutralization of the quencher and the acid, the acid is generated only in the portion irradiated initially on the pattern.

Thereafter, a heating process and a developing process are carried out to form a resist pattern as shown in Fig. 6 (d).

As described in Embodiments 1 and 2, the resist pattern forming method of the present invention enables formation of a high-resolution resist pattern by appropriately designing a resist, selecting an appropriate exposure light source, and the like by irradiating a pattern with a much lower exposure dose than usual can do.

In the above-mentioned specific example, the exposure light (II) in the exposure step (2) is selected so that the exposure light (I) does not react with the resist film (12) in the unirradiated area. . The exposure light may be selected so that the reaction of the resist film 12 with the resist film 12 in the region where the exposure light I is not irradiated takes place as the exposure light II in the exposure step (2).

Hereinafter, a resist pattern forming method according to another embodiment of the present invention will be described. The resist pattern forming method of the present embodiment includes a resist film forming step, an exposure step (1), an exposure step (2), and a developing step. The resist film forming step, the exposure step (1) and the developing step are the same as the resist film forming step (S101), the exposure step (1) (S105) and the developing step (S110 ), The description will be omitted.

In the exposure step (2), a pattern latent image is formed in the resist film in a state in which an acid and a sensitizer are generated by irradiation of the exposure light (I). Specifically, a pattern latent image is formed on the resist film in a state in which a sensitizer is present in the resist film. It is preferable that the exposure step (2) is performed in a state in which a lot of sensitizer is present. When a pattern latent image is formed in a state where an acid and a sensitizer are generated in the resist film, an acid can be generated from the [B] component by the action of the sensitizer by irradiation of the exposure light (II). Further, the resist pattern forming method of the present embodiment may further include a holding step of suppressing reduction of the amount of the acid and the sensitizer generated in the resist film. Since the holding process is performed in the same manner as the holding process (S105) of the embodiment described with reference to Figs. 1 to 6, the description is omitted here.

In the resist pattern forming method of the embodiment described with reference to Figs. 1 to 6, a sensitizer is generated in the resist film 12 and an acid is generated directly from the component [B] by the action of the sensitizer, Or the sensitizer is converted to the active substance? / Stable substance? 1, the active substance? / Stable substance? 1 is used to generate an acid from the [B] component, but the present invention is not limited thereto. A stable substance B1 is generated in the resist film and an acid is generated directly from the [B] component by the action of the stable substance B1, or after converting the stable substance B1 into the active substance? / Stable substance? 1, / An acid can be produced from the [B] component by the action of the stabilizing substance? 1. Hereinafter, a resist pattern forming method according to another embodiment of the present invention will be described.

The resist pattern forming method of the present embodiment includes a resist film forming step, a stable material generating step, a converting step, an exposure step (2), and a developing step. Since the resist film forming step and the developing step are performed in the same manner as the resist film forming step (S101) and the developing step (S110) of the embodiment described above with reference to Figs. 1 to 6, a description thereof will be omitted.

In the stable material generating step, a stable material is generated in the resist film by irradiation of the exposure light (I). Concretely, both the acid and the stable substance B1 from the [B] component are generated in the resist film 12 by the irradiation of the exposure light (I). The stabilizer B1 is, for example, an aromatic iodine compound or an aromatic sulfur compound.

In the conversion step, the stabilizing material B1 is converted in the irradiation region of the exposure light (I) in the resist film 12. Specifically, the stable substance B1 is converted into the active substance alpha / stable substance alpha 1 by control of the environment until the exposure step (2) (S107) described later is executed. As the method of conversion, an active gas atmosphere or an active liquid can be used as described in the above embodiment.

In the exposure step (2), the pattern latent image is formed on the resist film on which the stabilizing material B1 is generated by irradiation of the exposure light (II). Specifically, the exposure light (II) is a radiation which generates an acid from the [B] component by the action of the stabilizing substance B1 and the active substance? / Stabilizing substance? 1 in the irradiation region of the exposure light (I). At the irradiation site of the exposure light I of the resist film 12 irradiated by the exposure light (II), the stable substance B1 and the [B] component from the stable substance B1 and the active substance? / Stable substance? The acid (or a precursor of an acid or acid, which differs in structure from this acid) is produced.

Further, as described above, the exposure light I may be irradiated in a pattern and the exposure light II may be irradiated on one side. The radiation sensitive resin composition (I) suitably used when the exposure light (I) is irradiated in a pattern and the exposure light (II) is irradiated onto one surface will be described below.

The radiation-sensitive resin composition (I) of the present embodiment is a radiation-sensitive resin composition obtained by the action of an exposure light (I) containing radiation of a component (A) and a wavelength (I) And a [C] sensitizer precursor which is changed into a sensitizer by the action of the exposure light (I). In the resist film formed from the radiation sensitive resin composition (I) of the present embodiment, an acid is generated from the [B] component and a sensitizer is generated from the [C] sensitizer precursor by irradiation of the exposure light (I) , Even if only the exposure light (II) for accelerating the resist reaction by the sensitizer is irradiated, no acidity increase / decrease body is produced. The radiation sensitive resin composition (I) (the [A] component and the [C] sensitizer precursor) of the present embodiment is preferably transparent to the exposure light (II). Thus, when the exposure light (I) is irradiated to the [C] sensitizer precursor, a sensitizer showing strong absorption at different wavelengths is produced.

When the exposure light (II) is irradiated to the sensitizer produced from the [C] sensitizer precursor by irradiation of the exposure light (I) in the radiation sensitive resin composition (I) of the present embodiment, Thereby accelerating the generation of an acid from the component [B]. On the other hand, in the region of the unexposed resist film of the exposure light (I), even when the exposure light (II) is irradiated, no acidity increase or decrease is produced.

When the radiation-sensitive resin composition (I) of the present embodiment is irradiated with the exposure light (I) in a pattern, a sensitizer is produced in a pattern. Thereafter, when the exposure light (II) is irradiated to a predetermined region of the resist film, the resist reaction proceeds due to the sensitizer. Thus, a predetermined resist pattern can be easily formed.

The radiation sensitive resin composition (I) may further contain, in addition to the components [A] to [C], a polymer having a higher content of fluorine atoms and silicon atoms in total than the [D] quencher, [E] [F] polymer "), and may contain other components than the above components. Hereinafter, each component will be described.

[Component [A]]

The component [A] is a component whose solubility in a developing solution is changed by the action of an acid. The component [A] is not particularly limited as long as it has the above properties, and may include not only a polymer compound but also a low molecular compound, but a polymer compound is preferable. As the polymer compound, a first polymer (hereinafter also referred to as a "[A] polymer") containing a group capable of generating a polar group by dissociation of an acid-dissociable group by the action of an acid (hereinafter also referred to as " ).

([A] polymer)

[A] Polymer is a polymer containing group (a). The polymer [A] usually has a structural unit containing a group (a) (hereinafter also referred to as a &quot; structural unit (I) &quot;). The polymer [A] preferably has a structural unit (II) containing a lactone structure, a cyclic carbonate structure, a sultone structure or a combination thereof in addition to the structural unit (I) (II). &Lt; / RTI &gt; The polymer [A] may have one or more of the structural units described above. Hereinafter, each structural unit will be described.

(Structural unit (I))

The structural unit (I) is a structural unit containing the group (a).

(Group (a))

The group (a) is a group which generates a polar group by dissociation of an acid dissociable group by action of an acid. Examples of the group (a) include groups in which a hydrogen atom of the polar group is substituted with an acid dissociable group. Examples of the polar group include a hydroxyl group such as an alcoholic hydroxyl group and a phenolic hydroxy group, a carboxy group, a sulfo group, and an amino group.

As the group (a), there can be mentioned, for example, a group represented by the following formula (1).

In the formula (1), Y is a divalent group obtained by removing one hydrogen atom from a monovalent polar group. R ¹ is a monovalent acid dissociable group having 1 to 20 carbon atoms.

Examples of the acid dissociable group represented by R ¹ include a tertiary alkyl group, a tertiary cycloalkyl group, a 1-alkoxy substituted alkyl group, a 1-cycloalkyloxy substituted alkyl group and the like, 1-ethylcyclopentan-1-yl group, 1-i-propylcyclopentan-1-yl group, 2-ethyladamantan-2-yl group, 1-cyclohexylethoxyethyl group and the like .

Examples of the structural unit (I) include structural units represented by the following formula (2-1) (also referred to as structural units (I-1)), structural units represented by the following formula (2-2) I-2)), and the like.

In the formula (2-1), R ² is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ³ is a monovalent hydrocarbon group of 1 to 20 carbon atoms. R ⁴ and R ⁵ each independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms or an alicyclic structure having 3 to 20 reduced numbers formed by combining these groups together with the carbon atoms to which they are bonded.

In the formula (2-2), R ⁶ is a hydrogen atom or a methyl group. L ¹ is a single bond, -COO- or -CONH-. R ⁷ is a hydrogen atom or a monovalent hydrocarbon group of 1 to 20 carbon atoms. R ⁸ and R ⁹ are each independently a monovalent hydrocarbon group of 1 to 20 carbon atoms or a monovalent oxyhydrocarbon group of 1 to 20 carbon atoms.

Examples of the structural unit (I-1) include structural units represented by the following formulas (2-1-1) to (2-1-4) ) &Quot;) is preferable. As the structural unit (I-2), a structural unit represented by the following formula (2-2-1) (hereinafter also referred to as "structural unit (I-2-1)") is preferable.

R ² to R ⁵ in the formulas (2-1-1) to (2-1-4) are synonymous with the formula (2-1). n _p is independently an integer of 1 to 4;

In the formula (2-2-1), R ⁶ to R ⁹ are synonymous with the formula (2-2).

Examples of the structural unit (I-1) include structural units represented by the following formulas.

In the above formula, R ² is synonymous with the formula (2-1).

Examples of the structural unit (I-2) include structural units represented by the following formulas.

Wherein R &lt; ⁶ &gt; is as defined in formula (2-2).

As the structural unit (I-1), structural unit (I-1-1) and structural unit (I-1-2) are preferable, and structure derived from 1-alkylcyclopentan-1-yl (meth) And a structural unit derived from 2-alkyladamantan-2-yl (meth) acrylate are more preferable.

The structural unit (I-2) is preferably the structural unit (I-2-1), more preferably the structural unit derived from the 1-cycloalkyloxyalkane-1-yloxystyrene.

The lower limit of the content of the structural unit (I) is preferably 10 mol%, more preferably 20 mol%, further preferably 30 mol%, and preferably 40 mol%, based on the total structural units constituting the polymer [A] % Is particularly preferable. The upper limit of the content is preferably 80 mol%, more preferably 70 mol%, still more preferably 60 mol%, and particularly preferably 55 mol%. By setting the content ratio within the above range, the sensitivity, nano-edge roughness performance and resolution can be further improved.

[Structural unit (II)]

The structural unit (II) is a structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof. By having the polymer [A] having the structural unit (II), the sensitivity, the nano-edge roughness performance and the resolution can be further improved. Further, the adhesion between the resulting resist pattern and the substrate can be further improved.

Examples of the structural unit (II) include structural units represented by the following formulas.

Wherein R ^L1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

As the structural unit (II), structural units containing a lactone structure and structural units containing a cyclic carbonate structure are preferable, and structural units derived from (meth) acrylate having a group containing a lactone structure and cyclic carbon And a structural unit derived from (meth) acrylate having a group containing a nitrile structure is more preferable.

When the polymer [A] has the structural unit (II), the lower limit of the content of the structural unit (II) is preferably 10% by mole, preferably 20% by mole based on the total structural units constituting the polymer [A] , And still more preferably 30 mol%. The upper limit of the content is preferably 80 mol%, more preferably 70 mol%, still more preferably 60 mol%. By setting the content ratio of the structural unit (II) within the above range, the sensitivity, nano-edge roughness performance and resolution can be further improved. Further, the adhesion between the obtained resist pattern and the substrate can be further improved.

[Other structural units]

The polymer [A] may have other structural units in addition to the structural units (I) and (II). Examples of other structural units include structural units comprising a phenolic hydroxy group, a structural unit containing an alcoholic hydroxyl group, a structural unit comprising a ketonic carbonyl group, a cyano group, a carboxyl group, a nitro group, an amino group, or a combination thereof And structural units derived from a (meth) acrylic acid ester containing a monovalent alicyclic hydrocarbon group. The upper limit of the content ratio of the other structural units is preferably 20 mol%, more preferably 10 mol%, with respect to the total structural units constituting the polymer [A].

The lower limit of the content of the [A] component is preferably 70% by mass, more preferably 80% by mass, and even more preferably 85% by mass, based on the total solid content of the radiation sensitive resin composition (I). Means the total of the components other than the [E] solvent in the radiation sensitive resin composition (I).

The lower limit of the polystyrene-reduced weight average molecular weight (Mw) of the polymer [A] by gel permeation chromatography (GPC) is preferably 6,000, more preferably 7,000, even more preferably 8,000, and particularly preferably 10,000. The upper limit of the Mw is preferably 100,000, more preferably 30,000, even more preferably 20,000, and particularly preferably 15,000. By setting the Mw of the polymer [A] within the above range, film reduction can be suppressed.

The lower limit of the polystyrene reduced number average molecular weight (Mw) of the [A] polymer is preferably 3,000, more preferably 3,500, even more preferably 4,000, and particularly preferably 5,000. The upper limit of Mn is preferably 60,000, more preferably 20,000, even more preferably 15,000, and particularly preferably 10,000.

The lower limit of the ratio (Mw / Mn) of Mw to the polystyrene reduced number average molecular weight (Mn) of the polymer [A] is usually 1 and preferably 1.3. The upper limit of the ratio is preferably 5, more preferably 3, still more preferably 2, and particularly preferably 1.7.

Mw and Mn of the polymer in the present specification are values measured by GPC under the following conditions.

GPC Column: For example, two "G2000HXL", one "G3000HXL" and one "G4000HXL"

Column temperature: 40 DEG C

Elution solvent: tetrahydrofuran

Flow rate: 1.0 mL / min

Sample concentration: 1.0 mass%

Sample injection amount: 100 μL

Detector: differential refractometer

Standard material: monodisperse polystyrene

[Component [B]]

The component [B] is a component that generates an acid by the action of the exposure light (I). The content of the component [B] in the radiation-sensitive resin composition (I) may be contained as a component different from that of the component [A], and may be incorporated as part of the polymer [A] A] polymer, or both of them. The component [B], when contained as a component different from the component [A], may be in the form of a low molecular compound as described later (hereinafter also referred to as "[B] acid generator"), They may be in both forms.

[B] Examples of the acid generator include an onium salt compound, an N-sulfonyloxyimide compound, a sulfonimide compound, a halogen-containing compound, and a diazoketone compound.

Examples of the onium salt compound include a sulfonium salt, a tetrahydrothiophenium salt, an iodonium salt, a phosphonium salt, a diazonium salt, and a pyridinium salt.

Specific examples of the acid generator [B] include the compounds described in paragraphs [0080] to [0113] of JP-A No. 2009-134088, for example.

As the acid generator [B], a compound represented by the following formula (3) is preferable. It is considered that the diffusion length in the resist film of the acid generated by the interaction of [B] acid generator with the structure of the component [A] is more appropriately shortened by having the following structure, The sensitivity of the composition (I), the nano-edge roughness performance and the resolution can be further improved.

In the formula (3), R ^p1 is a monovalent group containing a ring structure having 6 or more ring members. R ^p2 is a divalent linking group. R ^p3 and R ^p4 each independently represent a hydrogen atom, a fluorine atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. R ^p5 and R ^p6 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group of 1 to 20 carbon atoms. n ^p1 is an integer of 0 to 10; n ^p2 is an integer of 0 to 10; and n ^p3 is an integer of 1 to 10. When n ^p1 is 2 or more, plural R ^p2 may be the same or different. When n ^p2 is 2 or more, plural R ^p3 may be the same or different, and plural R ^p4 may be the same or different. When n ^p3 is 2 or more, a plurality of R ^p5 may be the same or different, and a plurality of R ^p6 may be the same or different. X ^{&lt; + &} gt ^; is a monovalent, radiosensitive onium cation.

The monovalent radiation-sensitive onium cations represented by X ^&lt; ⁺ &gt; are cations decomposed by irradiation of the exposure light (I). In the exposed part, protons produced by the decomposition of these radiosensitive onium cations and sulfonic acids are generated from the sulfonate anions. Examples of the monovalent radiation sensitive onium cation represented by X ⁺ include a cation represented by the following formula (X-1) (hereinafter also referred to as a cation (X-1) (Hereinafter also referred to as &quot; cation (X-2) &quot;), and a cation represented by the following formula (X-3) .

R ^a1 , R ^a2 and R ^a3 in the formula (X-1) are each independently a substituted or unsubstituted, linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 12 carbon atoms A hydrocarbon group, -OSO ₂ -R ^P or -SO ₂ -R ^Q , or a cyclic structure in which two or more of these groups are joined together. R ^P and R ^Q are each independently a substituted or unsubstituted, linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted carbon number 6 To 12 aromatic hydrocarbon groups. k1, k2 and k3 are each independently an integer of 0 to 5; When R ^a1 to R ^a3 and R ^P and R ^Q are respectively plural, a plurality of R ^a1 to R ^a3 and R ^P and R ^Q may be the same or different.

In the formula (X-2), R ^b1 is a substituted or unsubstituted, linear or branched alkyl group having 1 to 8 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms. k4 is an integer of 0 to 7; When there are a plurality of R ^{b1 s} , a plurality of R ^{b1 s} may be the same or different, and a plurality of R ^{b1 s} may represent a cyclic structure formed by being mutually bonded.

R ^b2 is a substituted or unsubstituted, linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms. k5 is an integer of 0 to 6; When a plurality of R ^{b2 s} are present, a plurality of R ^{b2 s} may be the same or different and a plurality of R ^{b2 s} may represent a cyclic structure formed by mutually joining them. r is an integer of 0 to 3; R ^b3 is a single bond or a divalent organic group having 1 to 20 carbon atoms. and t is an integer of 0 to 2.

In the formula (X-3), R ^c1 and R ^c2 each independently represent a substituted or unsubstituted, linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, -OSO ₂ -R ^R or -SO ₂ -R ^S , or a cyclic structure in which two or more of these groups are joined together. R ^R and R ^S are each a substituted or unsubstituted carbon atoms, has 1 to 12 linear or branched alkyl group, a substituted or beach alicyclic hydrocarbon group or substituted in the ring having 5 to 25 or unsubstituted C 6 independently To 12 aromatic hydrocarbon groups. k6 and k7 are each independently an integer of 0 to 5; R ^c1 , R ^c2 , R ^R and R ^S may be the same or different when a plurality of R ^c1 , R ^c2 , R ^R and R ^S are respectively plural.

Examples of X ^+, a cation (X-1) and cation (X-3) is preferred among these, and triphenylsulfonium cation and 4-cyclohexylsulfonyldiazomethylsulfonyl phenyl diphenyl sulfonium cation and diphenyl iodonium cations than desirable.

Examples of the acid generator represented by the formula (3) include compounds represented by the following formulas (3-1) to (3-15) (hereinafter also referred to as the compounds (3-1) to (3-15) ), And the like.

In the formulas (3-1) to (3-15), X &lt; ^{+ &} gt ^; is a monovalent sensitizing radiation onium cation.

As the acid generator [B], onium salt compounds are preferable, and onium salt compounds of compound (3-15) and nonafluoro-n-butane-1-sulfonate are more preferable.

The [B] component may be contained in the polymer [A], for example, as a structural unit such as a structural unit represented by the following formula (4).

In the formula (4), R ^p7 is a hydrogen atom or a methyl group. L ² is a single bond, -O- or a divalent organic group having 1 to 20 carbon atoms. R ^p8 is a fluorinated alkanediyl group having 1 to 10 carbon atoms. X ^{&lt; + &} gt ^; is a monovalent, radiosensitive onium cation.

As R ^p7 , a hydrogen atom and a methyl group are preferable, and a methyl group is more preferable from the viewpoint of copolymerization of the monomer giving the structural unit represented by the formula (4).

As L ² , -COO- is preferable.

As R ^p8, a fluorinated alkanediyl group having 1 to 4 carbon atoms is preferable, a fluorinated alkanediyl group having 1 and 2 carbon atoms is more preferable, and a 1,2-difluoroethane-1,2-diyl group is more preferable.

The lower limit of the logarithm value (logP value) of the water / octanol partition coefficient of the acid generated from the [B] component is preferably 1.5, more preferably 2.0, and still more preferably 2.5. The upper limit of the log P value is preferably 12.0, more preferably 11.0, and even more preferably 10.5. By setting the log P value within the above range, in forming a resist pattern using a developer containing an organic solvent as a main component, the line edge roughness becomes better, and a resist pattern having an excellent in-plane uniformity of line width and bridge margin can be obtained . Although the reason for this is not clear, for example, by setting the log P value within the above range, the acid (B) component and the [B] component generated from the component [B] And can dissolve more quickly. That is, by setting the log P value to be not more than the upper limit, the hydrophobicity of the anion generated from the [B] component and the anion of the [B] component is within a suitable range. As a result, It is considered that aggregation due to minority interaction is suppressed, so that development proceeds uniformly. On the other hand, when the log P value is made to be equal to or lower than the lower limit described above, the acid generated from the [B] component and the [B] component are sufficiently dissolved in the developer (I), and as a result, precipitation of insoluble matter is suppressed. Further, by setting the log P value within the above range, the uniformity of the development is improved and the line pattern is less likely to swell. As a result, the bridge formation between the patterns is suppressed, thereby improving the bridge margin.

Here, the log P value is an algebraic value of the partition coefficient of octanol / water and is known as an important parameter indicating the affinity of the molecule. The method of obtaining the log P value of a compound is roughly divided into two methods: a method in which an experiment is actually measured and a method in which a value obtained by calculation is known.

Hereinafter, the method of calculating the logP value will be described. When the log P value is actually measured, it can be measured and measured by the method described in the following documents. In the case of calculating the logP value by calculation, the logP value (hereinafter also referred to as &quot; ClogP value &quot;) calculated by calculation can be calculated by the fragment method described in the following document or by using software packages 1 and 2 Can be obtained by calculation. The logP value in this specification indicates this ClogP value, and the numerical value of the logP value described in the specification is a numerical value of "ClogP value" calculated using the following software package 2.

C. Hansch and A. Leo, Substituent Constants for Correlation Analysis in Chemistry and Biology (John Wiley & Sons, New York, 1969)

Software Package 1: MedChem Software (Release 3.54, August 1991, Medicinal Chemistry Project, Pomona College, Claremont, CA)

Software Package 2: Chem Draw Ultra ver. 8.0 (April 2003, Cambridge Soft Corporation, USA)

(hereinafter also referred to as &quot; compound (I) &quot;) that generates an acid having a log P value of 1.5 to 12.0 I-1) &quot;) is preferable. By using the compound (I-1) as the acid generator [B], the line edge roughness becomes better in forming a resist pattern using a developer containing an organic solvent as a main component, and the uniformity of in- . The number of carbon atoms of the group containing a non-fluorine-substituted hydrocarbon skeleton is preferably 3 or more, more preferably 4 or more.

The non-fluorine-substituted hydrocarbon skeleton having 2 or more carbon atoms may be present at any position in the anion of the compound (I-1), but it is preferably a side chain of the anion.

As the acid from which the compound (I-1) is generated, for example, an acid represented by the following formula can be given.

Examples of the acid from which the compound (I) is generated include an acid represented by the following formula (I) or (I ').

In the above formulas (I) and (I '), A ₁ represents an alkylene group having 2 to 20 carbon atoms, a fluorinated alkylene group having 2 to 20 carbon atoms, an oxygen atom, Sulfur atom, -CO-, -COO- and the like. A ₂ and A ₃ are each independently a single bond, an oxygen atom or -N (Rxb) -. Rxb is a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, an alkyl group, an alkyl group having 1 to 20 carbon atoms, an alkyl group having 3 to 20 carbon atoms, or a cycloalkyl group or an oxacycloalkyl group having 3 to 20 carbon atoms. A ₄ is a single bond or -CO-. Ra is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, an aralkyl group having 7 to 20 carbon atoms, or an alkenyl group. n is 2 or 3; Rb is an n-valent linking group having 1 to 20 carbon atoms. When A ₃ is -N (Rxb) -, Ra and Rxb or Rb and Rxb are bonded to form an azacyclocalkane structure having 4 to 10 monocyclic or polycyclic condensed rings, or a 4- to 10-membered monocyclic or polycyclic alkoxycycloalkane Structure may be formed.

Examples of the substituent which each group may have include a halogen atom, a hydroxy group, a nitro group, a cyano group, a carboxy group, a cycloalkyl group, an aryl group, an alkoxy group, an acyl group and an acyloxy group.

As the sulfonic acids represented by the formulas (I) and (I '), sulfonic acids represented by the following formulas (IA) to (IC) and (I'A) to (I'C) are preferable.

Ra 'in the formulas (IA) to (IC) and (I'A) to (I'C) agrees with Ra in the formula (I). Rb and n are synonymous with Rb and n in the formula (I '). R 1 'is an alkyl group, an aryl group, an aralkyl group or an alkenyl group, R x' is the same as R xb in the formulas (I) and (I '), n 1 is an integer of 1 to 10, A ₅ is a single bond, -O-, an alkylene group, a cycloalkylene group or an arylene group.

The alkylene group and cycloalkylene group represented by A ₅ are preferably an alkylene group which is not fluorine-substituted and a cycloalkylene group which is not fluorine-substituted. In the above formula (IA), it is preferable that Ra 'and Rx' are combined to form a ring. By forming a ring structure, the stability of the compound represented by the formula (IA) is improved and the storage stability of the radiation-sensitive resin composition (I) containing the same is improved. The number of carbon atoms of the formed ring is preferably 4 to 20. Examples of the alkyl group, aryl group, aralkyl group and alkenyl group represented by Ra "include the same groups exemplified as Ra. N1 + n2 is preferably 2 to 8, more preferably 2 to 6 Do.

As the sulfonic acid represented by the formulas (I) and (I '), a sulfonic acid represented by the following formula is preferable.

Of these, sulfonic acids containing a fluorine-substituted hydrocarbon skeleton having 2 or more carbon atoms are preferable. As such a sulfonic acid, for example, a compound represented by the following formula can be given.

As the compound (I), it is also preferable to generate a sulfonic acid represented by the following formula (II).

In the formula (II), Rf is an organic group having a fluorine atom or a fluorine atom. R _a1 and R _b1 each independently represent an alkyl group, an aryl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an aralkyl group, an aralkyloxy group, a cycloalkoxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, An acyl group, an acyl group, an acyl group, an alkenyl group, an alkenyl group, an arylcarbonyloxy group, an alkylcarbonyloxy group, an alkylaminocarbonyl group, an alkylcarbonylamino group, an alkylsilyloxy group, a cyano group, A group having a linking group such as an oxygen atom, a sulfur atom or -COO- between one or a plurality of carbon-carbon atoms, and a monovalent group having 2 to 30 carbon atoms in which some or all of the hydrogen atoms of these groups are substituted with a substituent . Ar is an aromatic group having 6 to 20 carbon atoms and may have a tetravalent substituent. X is -SO-, -SO ₂ -, a -O- or -S-. l 'is an integer of 0 to 6; m 'is an integer of 0 to 5; n 'is an integer of 0 to 5. When l 'and n' are two or more, a plurality of R _a1 and R _b1 may be the same or different. Rf is an organic group having a fluorine atom or a fluorine atom. When m 'is 2 or more, a plurality of Rf may be the same or different.

The sum of the carbon numbers of Rf and R _a1 and R _b1 is preferably 4 to 34 carbon atoms, more preferably 6 to 30 carbon atoms, still more preferably 8 to 24 carbon atoms. The diffusibility of the acid can be adjusted by adjusting the number of carbon atoms of Rf and R _a1 and R _b1 , and the resolution is improved.

As the sulfonic acid represented by the formula (II), a sulfonic acid represented by the following formula (IIa) is preferable, a sulfonic acid represented by the following formula (IIb) is more preferable, and a sulfonic acid represented by the following formula (IIc) Do.

The formula (IIa), (IIb) and (IIc) of _{R a1, Rf, X, l} ', m', n ' is R _a1, Rf, X, l in the formula (II)', m ' , n '. R is a monovalent organic group.

As the sulfonic acid represented by the formula (II), a sulfonic acid represented by the following formula is preferable.

Of these, sulfonic acids having a fluorine-substituted hydrocarbon skeleton having 2 or more carbon atoms are preferable.

Examples of the sulfonic acid generating compound represented by the above formulas (I), (I ') and (II) include sulfonium salt compounds and iodonium salts of sulfonic acids represented by the above formulas (I), (I' Compounds and ester compounds of sulfonic acids represented by the following formulas (I), (I ') and (II) are preferable, and compounds represented by the following formulas (B1) to (B5) are more preferable.

In the formula (B1), R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents a monovalent organic group. Two of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ may be bonded to form a ring structure.

In the formula (B2), R ₂₀₄ and R ₂₀₅ are each independently a substituted or unsubstituted aryl group, an alkyl group or a cycloalkyl group.

In the formula (B3), A is a substituted or unsubstituted alkylene, alkenylene or arylene group.

In the formula (B4), R &lt; _{208 &gt;} is a substituted or unsubstituted alkyl group, cycloalkyl group or aryl group. R ₂₀₉ is an alkyl group, a cyano group, an oxoalkyl group or an alkoxycarbonyl group.

In the formula (B5), R ₂₁₀ and R ₂₁₁ each independently represent a hydrogen atom, an alkyl group, a cyano group, a nitro group or an alkoxycarbonyl group. R ₂₁₂ is a hydrogen atom, an alkyl group, a cyano group or an alkoxycarbonyl group.

X ^- in the formulas (B1) to (B5) is a sulfonic acid anion from which a proton is removed from the sulfonic acid represented by the formula (I), (I ') or (II).

The number of carbon atoms of the organic group of R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is usually 1 to 30, preferably 1 to 20. The ring structure formed by bonding two of R ₂₀₁ to R ₂₀₃ may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond or a carbonyl group in the ring.

Examples of the organic groups represented by R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds represented by the following formulas (B1a), (B1b) and (B1c).

The compound (I) may be a compound having a plurality of structures represented by the formula (B1). For example, a compound having the formula with at least one of the compound of R ₂₀₁ to R ₂₀₃ represented by (B1), to another compound of the structure at least bound and one of R ₂₀₁ to R ₂₀₃ is represented by the formula (B1) Lt; / RTI &gt;

As the compound represented by the above formula (B1), the following compounds (B1a), (B1b) and (B1c) are preferable.

The compound (B1a) is an arylsulfonium compound in which at least one of R ₂₀₁ to R ₂₀₃ in the compound (B1) is an aryl group, that is, a compound having an arylsulfonium cation. In the arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be an aryl group, and some of R ₂₀₁ to R ₂₀₃ may be an aryl group, and the remainder may be an alkyl group or a cycloalkyl group.

The compound (B1b) is a compound in which each of R ₂₀₁ to R ₂₀₃ in the formula (B1) is independently an organic group having no aromatic ring and is a group selected from an alkyl group, a cycloalkyl group, an allyl group and a vinyl group. Here, the aromatic ring also includes an aromatic heterocyclic ring having a hetero atom. The number of carbon atoms of the organic group having no aromatic ring is usually 1 to 30, preferably 1 to 20.

The compound (B1c) is a compound represented by the following formula (B1c), that is, an aryl acyl methyl sulfonium salt compound.

In the formula (B1c), R ₂₁₃ is a substituted or unsubstituted aryl group. R ₂₁₄ and R ₂₁₅ are each independently a hydrogen atom, an alkyl group or a cycloalkyl group. Y ₂₀₁ and Y ₂₀₂ each independently represent a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group or vinyl group. R ₂₁₃ and R ₂₁₄ may combine to form a ring structure. And R ₂₁₄ and R ₂₁₅ may combine to form a ring structure. Y ₂₀₁ and Y ₂₀₂ may combine to form a ring structure. X ^- is a sulfonic acid anion in which a hydrogen atom is removed from the sulfonic acid represented by the above formulas (I), (I ') and (II).

As the compound (I), the compound represented by the formula (B1) is preferable, and the compounds (B1a) to (B1c) are more preferable.

The compound (I) preferably has a triphenylsulfonium structure.

As the compound (I), a triphenylsulfonium salt compound having a fluorine-substituted alkyl group or a cation containing a cycloalkyl group is preferable.

As the compound (I), the compounds represented by the following formulas b1 to b84 are preferable.

When the component [B] is the acid generator [B], the lower limit of the content of the acid generator [B] is preferably 0.1% by mass, preferably 1% by mass, based on the total solid content of the radiation sensitive resin composition (I) , More preferably 5 mass%, even more preferably 10 mass%, even more preferably 18 mass%, and most preferably 20 mass%. The upper limit of the content is preferably 50% by mass, more preferably 40% by mass, still more preferably 35% by mass, particularly preferably 30% by mass, particularly preferably 27% by mass and most preferably 25% desirable.

When the component [B] is the acid generator [B], the lower limit of the content of the acid generator [B] is preferably 0.1 part by mass, more preferably 1 part by mass, and most preferably 5 parts by mass with respect to 100 parts by mass of the component [A] More preferably 10 parts by mass, particularly preferably 15 parts by mass, most preferably 20 parts by mass, most preferably 20 parts by mass. The upper limit of the content is preferably 100 parts by mass, more preferably 70 parts by mass, still more preferably 50 parts by mass, particularly preferably 40 parts by mass, most preferably 35 parts by mass, most preferably 30 parts by mass.

By setting the content of the acid generator [B] within the above range, the sensitivity, the nano-edge roughness performance and the resolution can be further improved. The [B] component may be used alone or in combination of two or more.

([C] sensitizer precursor)

[C] The sensitizer precursor is a compound which is changed into a sensitizer by the action of the exposure light (I). The form of containing the [C] sensitizer precursor in the radiation-sensitive resin composition (I) may be contained as a component different from the component [A], and may be contained as a part of the polymer [A] May be contained in the polymer [A], or may be in a form containing both of them. When the [C] sensitizer precursor is contained as a component different from the [A] component, it may be in the form of a low molecular weight compound, in the form of a polymer, or in both of them.

[C] Absorbance (I ^P) ratio ^{((I PP) / (I} P)) for at a wavelength (II) of the sensitized body in absorbance (I ^PP) at a wavelength (II) of the sensitized body precursor Is preferably 0.2, more preferably 0.15, and even more preferably 0.1. The lower limit of the value of the ratio is not particularly limited, but is, for example, 0.05. By setting the value of the ratio of the absorbance of the [C] sensitizer precursor to the sensitizer at the wavelength (II) within the above range, the efficiency of the pattern forming method can be further increased. As a result, And the resolution can be further improved.

[C] As the sensitizer precursor, for example, bis (4-methoxyphenyl) methanol (DOMeBzH), dimethoxybenzhydrol derivative (DOBzMM), trimethoxybenzhydrol (TriOMeBzH) and the like can be given.

When the resist film is irradiated with the exposure light (I), a sensitizer is generated from the [C] sensitizer precursor. For example, the exposure light (I) is an electron beam or EUV light. Alternatively, the exposure light I may be ArF laser light.

When the exposure light is irradiated with the exposure light (II), a latent image is formed on the resist film. As described above, the irradiation of the exposure light (II) may be performed in the air or in a vacuum. For example, the exposure light (II) is UV light.

Further, the radiation sensitive resin composition (I) does not absorb the exposure light (II). Typically, radiation having a longer wavelength than the exposure light I is used as the exposure light II. It is preferable that the exposure light (I) does not substantially contain the radiation of the wavelength (II) included in the exposure light (II). Since the exposure light (I) does not substantially contain the radiation of the wavelength (II), the contrast of the resist pattern can be better imparted, and as a result, the sensitivity, nano edge roughness performance and resolution can be further improved . However, the present invention is not limited to this, and radiation having a shorter wavelength than the exposure light (I) may be used as the exposure light (II).

([D] Quanta)

The radiation-sensitive resin composition (I) may contain [D] quencher. For example, [D] Quanta may be neutralizing with acid. The [D] quencher may also be to deactivate the reaction intermediate which is a precursor of the sensitizer.

Examples of the [D] quencher include an amine compound, an amide group-containing compound, a urea compound, and a nitrogen-containing heterocyclic compound.

Examples of the amine compound include monoalkyl amines such as n-hexylamine; Dialkylamines such as di-n-butylamine; Trialkylamines such as triethylamine; Aromatic amines such as aniline and 2,6-i-propylaniline; Diamines such as ethylenediamine, N, N, N ', N'-tetramethylethylenediamine; Polyamine compounds such as polyethyleneimine and polyallylamine; And polymers such as dimethylaminoethyl acrylamide.

Examples of the amide group-containing compound include, but are not limited to, formaldehyde, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, N-methylpyrrolidone, and the like.

Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea And the like.

As the nitrogen-containing heterocyclic compound, for example, pyridine such as pyridine or 2-methylpyridine; Morpholines such as N-propylmorpholine and N- (undecylcarbonyloxyethyl) morpholine; Pyrazine, and pyrazole.

As the nitrogen-containing compound, a compound having an acid-dissociable group may also be used. Examples of the nitrogen-containing organic compound having an acid dissociable group include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycar (T-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) di-n-octylamine, N- N-tert-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine, and the like can be used. .

As the [D] quencher, a photodegradable base which is weakly sensitized by exposure to generate a weak acid may be used. Examples of the photodegradable base include an onium salt compound decomposed by exposure to lose acid diffusion controllability and the like. Examples of the onium salt compound include a sulfonium salt compound represented by the following formula (5-2-1) and an iodonium salt compound represented by the following formula (5-2-2).

The formula (5-2-1) and (5-2-2) of the R ¹³ to R ¹⁷ are each independently a hydrogen atom, alkyl group, alkoxy group, hydroxyl group or halogen atom. E ^-, and Q ^- are each independently, OH ^- or an anion represented by the formula ^{(5-2-a) -, R} β -COO -, R β -SO 3. Provided that R ^? Is an alkyl group or an aralkyl group.

In the formula (5-2-a), R ¹⁸ is an alkyl group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. u is an integer of 0 to 2; When u is 2, two R &lt; ¹⁸ &gt; may be the same or different.

Examples of the photodegradable base include compounds represented by the following formulas.

Among them, sulfonium salts are preferable, triarylsulfonium salts are more preferable, triphenylsulfonium salts and 4-cyclohexylsulfonylphenyldiphenylsulfonium salts are more preferable, and salicylate compounds, (Cyclohexyloxycarbonyl) ethane-1-sulfonate compound and 1,2-di (norbornanalactone-1-sulfonate) 2-yloxycarbonyl) ethane-1-sulfonate compound is particularly preferable.

When the radiation-sensitive resin composition (I) contains [D] quencher, the lower limit of the content of [D] quencher is preferably 0.1 part by mass, more preferably 0.5 part by mass, per 100 parts by mass of component [A] , More preferably 1 part by mass, and particularly preferably 3 parts by mass. The upper limit of the content is preferably 20 parts by mass, more preferably 15 parts by mass, further preferably 10 parts by mass.

([E] solvent)

The radiation sensitive resin composition (I) usually contains a [E] solvent. The solvent [E] is not particularly limited as far as it is a solvent capable of dissolving or dispersing at least the [A] component, the [B] component, the [C] sensitizer precursor and the [D]

Examples of the [E] solvent include those exemplified as organic solvents contained in the developing solution used in the above-described developing step.

Of these, ester solvents and ketone solvents are preferable, and polyhydric alcohol partial ether acetate solvents, cyclic ketone solvents and lactone solvents are more preferable, and propylene glycol monomethyl ether acetate, cyclohexanone and gamma -butyrolactone Is more preferable. The radiation-sensitive resin composition (I) may contain one or more [E] solvents.

([F] polymer)

The radiation sensitive resin composition (I) may contain a [F] polymer. The [F] polymer is a polymer having a higher content of fluorine atoms and silicon atoms in total than the component [A].

The distribution of the [F] polymer tends to be unevenly distributed in the vicinity of the surface of the resist film due to the oil property of the [F] polymer in the resist film when the resist film is formed by the radiation-sensitive resin composition (I) It is possible to inhibit development defects by suppressing elution of an acid generator, an acid diffusion control agent, and the like in the liquid immersion medium during liquid immersion exposure, or by improving the solubility in a developer.

The lower limit of the total content by mass of the fluorine atom and silicon atom in the [F] polymer is preferably 1% by mass, more preferably 2% by mass, even more preferably 4% by mass, and particularly preferably 7% by mass. The upper limit of the total mass content is preferably 60 mass%, more preferably 40 mass%, and still more preferably 30 mass%. By setting the content of the total mass in the above range, the hydrophobicity of the surface of the resist film can be more appropriately adjusted. The content of the total mass of the fluorine atom and the silicon atom in the polymer can be calculated from the structure of the polymer obtained by ¹³ C-NMR spectrum measurement or the like.

Examples of the [F] polymer include a polymer having a fluorine atom and a polymer having a silicon atom.

(A polymer having fluorine atoms)

The polymer [F] is a polymer comprising a structural unit represented by the following formula (6-1) (hereinafter also referred to as a "structural unit (Fa)") and a structural unit represented by the following formula (6-2) (Fb) &quot;). [F] The polymer may have one or more structural units (Fa) and structural units (Fb), respectively.

(Structural unit (Fa))

The structural unit (Fa) is a structural unit represented by the following formula (6-1). The [F] polymer can have a fluorine atom content by adjusting the structural unit (Fa).

In the formula (6-1), R ¹⁹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. L ³ is a single bond, an oxygen atom, a sulfur atom, -CO-O-, -SO ₂ -O-NH-, -CO-NH- or -O-CO-NH-. R ²⁰ is a monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms or a monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms.

As R ¹⁹ , a hydrogen atom and a methyl group are preferable, and a methyl group is more preferable from the viewpoint of copolymerization of a monomer giving the structural unit (Fa).

Examples of the monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms represented by R ²⁰ include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, a 2,2,3,3- Pentafluoropropyl group, a 1,1,1,3,3,3-hexafluoropropyl group, a perfluoro n-propyl group, a perfluoro i-propyl group, a perfluoro n-butyl group, A perfluoro i-butyl group, a perfluoro t-butyl group, a 2,2,3,3,4,4,5,5-octafluoropentyl group, and a perfluorohexyl group.

Examples of the monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R ²⁰ include a monofluorocyclopentyl group, a difluorocyclopentyl group, a perfluorocyclopentyl group, a monofluorocyclohexyl group, A perfluorocyclohexylmethyl group, a fluoronorbornyl group, a fluoroamantyl group, a fluoroboronyl group, a fluoroisobornyl group, a fluoro-tricyclodecyl group, a fluorotetracyclodecyl group, .

As the structural unit (Fa), 2,2,2-trifluoroethyl (meth) acrylate is preferable.

When the [F] polymer has the structural unit (Fa), the lower limit of the content ratio of the structural unit (Fa) is preferably 5 mol%, and preferably 10 mol%, relative to the total structural units constituting the [F] , And still more preferably 20 mol%. The upper limit of the content is preferably 95 mol%, more preferably 75 mol%, still more preferably 50 mol%. By setting the content ratio of the structural unit (Fa) within the above range, the fluorine atom content can be adjusted more appropriately.

(Structural unit (Fb))

The structural unit (Fb) is a structural unit represented by the following formula (6-2). Since the polymer [F] has a hydrophobic property by having the structural unit (Fb), the dynamic contact angle of the resist film surface formed from the radiation-sensitive resin composition (I) can be further improved.

In the formula (6-2), R ²¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ²² is 1 to 20 carbon atoms in the (s + 1) valent hydrocarbon group, or an oxygen atom at the terminal of R ²³ side of the hydrocarbon group, a sulfur atom, -NR'-, carbonyl, -CO-O- or -CO- NH-. R 'is a hydrogen atom or a monovalent organic group. R ²³ is a single bond, a divalent straight chain hydrocarbon group having 1 to 10 carbon atoms, or a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms. X ¹ is a divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms. A ¹ is an oxygen atom, -NR "-, -CO-O- * or -SO ₂ -O- * R" is a hydrogen atom or a monovalent organic group. * Represents a bonding site which binds to R ²⁴ . R ²⁴ is a hydrogen atom or a monovalent acid dissociable group, an alkali dissociable group or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent. s is an integer of 1 to 3; Provided that when s is 2 or 3, plural R ^{23 s} may be the same or different, plural X ^{1 s} may be the same or different, plural A ^{1 s} may be the same or different, plural the R ²⁴ may be the same or different.

Examples of the structural unit (Fb) include structural units represented by the following formulas (6-2-1) to (6-2-3).

In the formulas (6-2-1) to (6-2-3), R ^{22 '} is a divalent hydrocarbon group having 1 to 20 carbon atoms. R ²¹ , R ²² , X ¹ , R ²⁴ and s are as defined in the above formula (6-2). R ^{23 '} is a group in which an oxygen atom, a sulfur atom, -NR'-, a carbonyl group, -CO-O- or -CO-NH- is bonded to the terminal on the X ¹ side of a divalent hydrocarbon group having 1 to 20 carbon atoms. When s is 2 or 3, plural X ^{1 s} may be the same or different, and a plurality of R ^{24 s} may be the same or different.

When the [F] polymer has the structural unit (Fb), the lower limit of the content ratio of the structural unit (Fb) is preferably 5 mol%, and preferably 10 mol%, relative to the total structural units constituting the [F] , Still more preferably 15 mol%. The upper limit of the content is preferably 90 mol%, more preferably 70 mol%, still more preferably 50 mol%. By setting the content ratio of the structural unit (Fb) within the above range, the fluorine atom content can be adjusted more appropriately.

(Structural unit (Fc))

The polymer [F] may have, in addition to the structural units (Fa) and (Fb), a structural unit containing an acid dissociable group (hereinafter also referred to as "structural unit (Fc)") Except for those applicable. When the [F] polymer has the structural unit (Fc), the shape of the resulting resist pattern becomes better. Examples of the structural unit (Fc) include structural units (I) in the above-mentioned [A] polymer.

When the [F] polymer has the structural unit (Fc), the lower limit of the content ratio of the structural unit (Fc) is preferably 5 mol%, and preferably 25 mol%, relative to the total structural units constituting the [F] , And still more preferably 60 mol%. The upper limit of the content is preferably 90 mol%, more preferably 80 mol%, still more preferably 75 mol%.

(Other structural units)

In addition to the above structural units (Fa) to (Fc), the [F] polymer may contain, for example, a structure containing an alkali-soluble group, a lactone structure, a cyclic carbonate structure, a sultone structure, , And structural units derived from (meth) acrylate containing a monovalent alicyclic hydrocarbon group having a comparative solubility. Examples of the alkali-soluble group include a carboxy group, a sulfonamide group, and a sulfo group. Examples of the structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure or a combination thereof include the structural unit (II) in the above-mentioned [A] polymer.

The upper limit of the content ratio of the other structural units is preferably 30 mol%, more preferably 20 mol%, based on the total structural units constituting the [F] polymer.

When the radiation-sensitive resin composition (I) contains the [F] polymer, the lower limit of the content of the [F] polymer is preferably 0.5 parts by mass, more preferably 1 part by mass, per 100 parts by mass of the component [A] , More preferably 2 parts by mass. The upper limit of the content is preferably 20 parts by mass, more preferably 10 parts by mass, further preferably 7 parts by mass.

(Other components)

The radiation-sensitive resin composition (I) may contain other components. Examples of other components include surfactants, alicyclic skeleton-containing compounds, and the like. The radiation-sensitive resin composition (I) may contain one or more kinds of other components.

[Method of producing the radiation-sensitive resin composition (I)] [

The radiation-sensitive resin composition (I) can be obtained, for example, by mixing the [A] component, the [B] component, the [C] sensitizer precursor, the [D] And the like. After mixing, the radiation-sensitive resin composition (I) is preferably filtered, for example, with a filter having a pore diameter of about 0.2 탆. The lower limit of the solid content concentration of the radiation sensitive resin composition (I) is preferably 0.1% by mass, more preferably 0.5% by mass, and further preferably 1% by mass. The upper limit of the solid content concentration is preferably 50 mass%, more preferably 30 mass%, and even more preferably 10 mass%.

Since the radiation sensitive resin composition (I) is a chemically amplified type, the sensitizer absorbs the exposure light (II) to generate an acid and a sensitizer, whereby the resist reaction proceeds. For example, the excitation state of the sensitizer is generated by irradiation of the exposure light (II). By the electron transfer from the excited state of the sensitizer, the component [B] dissociates by dissociative electron addition reaction to generate an acid and a sensitizer before excitation. When the exposure light (II) is continuously irradiated in the region where the sensitizer is present, the acid and the sensitizer are produced until the [B] component is almost lost.

According to this radiation-sensitive resin composition (I), in the exposure step (I), a sensitized body having a narrowed concentration distribution due to a quencher that reduces a sensitizer is subjected to optical flood exposure, . The acid generator is decomposed in the electron transfer reaction from the excited state of the sensitizer to generate an acid and a sensitizer before excitation. This acid is generated until the acid generator almost disappears in the region where the sensitizer is present. Further, at the portion where the remaining amount of the acid generator is decreased, the acid generating reaction is slowed down and saturated. The concentration distribution of the acid after the neutralization of the acid and the quencher is constant at almost the center of the irradiated region of the exposure light I and falls very steeply at the end. The acid is formed so that the slope change at the end has a rapid concentration distribution. As described above, high sensitivity, high resolution, low LER, and photon shot noise can be solved at the same time.

Hereinafter, a suitable use example of the radiation sensitive resin composition (I) of the present embodiment will be described.

[Practical example 5]

Sensitive radiation-sensitive resin composition (I) is prepared. The radiation sensitive resin composition (I) contains the [A] component, the [B] component and the [C] sensitizer precursor. In the present embodiment, the radiation sensitive resin composition (I) is a composition which generates a sensitizer by irradiation of the exposure light (I) and accelerates the resist reaction by the sensitizer without irradiating the exposure light (I) Even when the exposure light (II) is irradiated, a sensitizer is not produced.

A resist film is formed using the radiation sensitive resin composition (I). The resist film is formed on the substrate by, for example, a spin coating method.

The exposure step (1) is carried out. In the exposure step (1), the exposure light (I) is irradiated as a pattern. A sensitizer is generated in the portion irradiated with the exposure light (I). At this time, an acid is generated together with the sensitizer. In this exposure step (1), since the amount of irradiation on the pattern is low, no resist pattern is formed on the resist film even when the development step is carried out. In Example 5, the decrease in the amount of the acid and / or the sensitizer in the resist film may be suppressed by the above-described holding step, but it may not be suppressed.

The exposure step (2) is carried out simultaneously with the exposure step (1) or after the exposure step (1) is executed. In the exposure step (2), the exposure light (II) is irradiated on one surface. As shown in Fig. 5, as the exposure light (II), the exposure light (II) which does not generate an acid and a sensitizer in the resist film in the region where the exposure light (I) . An acid is generated by the reaction of the sensitizer and the acid generation by the irradiation of the exposure light (II).

As described above, in the exposure step (2), even if the exposure light (II) is irradiated on one surface, a sensitizer is generated only in the portion irradiated with the pattern image for the first time. Activated. As a result, a large amount of acid is generated only at the initial pattern-irradiated portion, and after the neutralization of the quencher and the acid, the latent image of the acid is generated only at the initial pattern-irradiated portion. Thereafter, a heating process and a developing process are performed to form a resist pattern.

[Example 6]

A resist film is formed using the radiation sensitive resin composition (I). The exposure step (1) is carried out. In the exposure step (1), the exposure light (I) is irradiated as a pattern. And an acid and a sensitizer are generated in the portion irradiated with the exposure light (I). At this time, since the amount of irradiation on the pattern is low, no resist pattern is formed on the resist film even when the development process is performed. In Example 6, the decrease in the amount of the acid and / or the sensitizer in the resist film may be suppressed by the above-described holding step, but it may not be suppressed.

The exposure step (2) is carried out simultaneously with the exposure step (1) or after the exposure step (1) is executed. In the exposure step (2), the exposure light (II) is irradiated on one surface. As the exposure light (II), in the resist film unexposed to the exposure light (I), substantially no sensitizer is produced from the [B] component and the [C] sensitizer precursor, the exposure light (II) for activating only? 1 is appropriately selected. The irradiation of the exposure light (II) causes the formation of a sensitizer from the [C] sensitizer precursor and / or the formation of an acid (or precursor of an acid or acid which differs in structure from the [B] component) from the [B] component . The sensitizer reacts with the active atmosphere or the active liquid and is again converted into the active substance alpha / stable substance alpha 1.

As described above, in the exposure step (2), even when the exposure light (II) is irradiated on one surface, an acid is generated only in the first irradiated portion in the pattern image, and the active state? / Stable substance? It is reproduced by one-sided survey. As a result, a large amount of acid is generated only at the initial pattern-irradiated portion, and after the neutralization of the quencher and the acid, the latent image of the acid is generated only at the initial pattern-irradiated portion. Thereafter, a heating process and a developing process are performed to form a resist pattern.

[Practical example 7]

Hereinafter, the seventh specific example will be described with reference to Figs. First, a radiation-sensitive resin composition (I) is prepared. The radiation sensitive resin composition (I) is a polymer which is a component of the component (A), such as? -Butyrolactone-? -Methacrylate, 2- (1-adamantyl) (4-methoxyphenyl) methanol (DOMeBzH) as a [C] sensitizer precursor, wherein the amount of the bis (4-methoxyphenyl) [B] iodo salt (R ₂ IX) to contain and ([a] component with respect to 100 parts by weight, [C] or decrease body precursor 4.6 parts by weight (3 parts by mass or more to 30 parts by mass as an acid generator (PAG) Preferably 4 parts by mass or more and 10 parts by mass or less), and 4.6 parts by mass (3 parts by mass or more and 30 parts by mass or less, preferably 4 parts by mass or more and 10 parts by mass or less) of the acid generator [B].

Next, the radiation-sensitive resin composition (I) is spin-coated on a silicon substrate and prebaked. The spin conditions are changed according to the solid content concentration of the radiation sensitive resin composition (I), but the spin coating conditions are 1500 rpm, 30 seconds, prebaking at 100 캜 and 60 seconds. The amount of addition of the quencher is intended to be a mass of about 1/10 of the amount of the acid generator (B) to be added, but is preferably 0.1% by mass or more and 3.0% by mass or less based on the total solid content of the radiation sensitive resin composition (I) Is not less than 0.3 mass% and not more than 1.2 mass%.

Fig. 7 shows a chemical reaction formula performed in this embodiment. The resist film is irradiated with an electron beam on the pattern. The electron beam exposure on the pattern was performed using an EB exposure system (JEOL, beam current: 12.5 and 28 pA, <1E ^-4 Pa) of JSM-6500F 30 keV equipped with beam draw (Tokyo Technology) Loses.

It is considered that the reaction mechanism in the resist film when the electron beam on the pattern is irradiated proceeds according to the formulas (a-1) to (a-5) in Fig. As shown in the formula (a-1), the resist film is ionized by irradiation of electron beams on the pattern to generate mainly polymer radical cations (RH ⁺ ) and electrons (e ^- ). The polymer radical cation (RH ⁺ ) reacts with the polymer (RH) and is separated into a radical P · and a cation (RH (H ⁺ )).

As shown in the formula (a-2), the electrons e ^- react with the [B] acid generator (R ₂ I ⁺ X ^- ) to form a neutral molecule (RI), a radical ^- ).

As shown in the formula (a-3), the cation (RH (H ⁺ )) reacts with the anion (X ^- ) to produce the polymer (RH) and the acid (HX).

Further, as shown in the formula (a-4), when the radical (R) reacts with DOMeBzH, a radical (DOMeBzH) is produced. As shown in the formula (a-5), this radical reacts with the [B] acid generator (R ₂ I ⁺ X ^- ) and electrons move to generate a cation (DOMeBzH ⁺ ). Further, as shown in the formula (a-6), the sensitizer (DOMeBzO) and the acid (HX) are produced by the movement of the both from the cation (DOMeBzH ⁺ ) to the anion.

Subsequently, after irradiating the electron beam on the pattern, Flood UV (320 and 365 nm) is irradiated at room temperature. It is considered that the reaction mechanism in the resist film when the flood UV is irradiated proceeds according to the formula (b-1) in Fig. When Flood UV is irradiated, the sensitizer (DOMeBzO) is excited. (DOMeBzO +), a neutral molecule (RI), a radical (R) and an anion (X) by the movement of electrons from the sensitizer (DOMeBzO) in the excited state to the acid generator (PAG) ^- ) is generated. In addition, when flood UV is irradiated, a reaction similar to the reaction when the electron beam is irradiated on the pattern proceeds, and the acid is efficiently produced by the chain reaction.

Example

Hereinafter, the present invention will be described concretely with reference to examples, but the present invention is not limited to these examples. Methods for measuring various physical properties are shown below.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)] [

The Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) using a GPC column (two "G2000HXL", one "G3000HXL" and one "G4000HXL") manufactured by Tosoh Corporation under the following conditions.

Eluent: tetrahydrofuran (Wako Pure Chemical Industries, Ltd.)

Flow rate: 1.0 mL / min

Sample concentration: 1.0 mass%

Sample injection amount: 100 μL

Detector: differential refractometer

Standard material: monodisperse polystyrene

[Content of low molecular weight component]

The content (mass%) of the low molecular weight component (component having a molecular weight of 1,000 or less) in the polymer of component [A] was determined by high performance liquid chromatography (HPLC) using "Inertsil ODS- 250 mm) was used, and measurement was made under the following conditions.

Eluent: Acrylonitrile / 0.1% by mass aqueous solution of phosphoric acid

Flow rate: 1.0 mL / min

Sample concentration: 1.0 mass%

Sample injection amount: 100 μL

Detector: differential refractometer

[ ¹³ C-NMR analysis]:

(JNM-EX400, manufactured by Nihon Denshi Co., Ltd.) and DMSO-d ₆ as a measurement solvent.

&Lt; Synthesis of Component [A] >

The polymer (F-1) of the polymer (A-1) to the polymer (A-10) and the polymer (F-1) Compounds (M-1) to (M-9) ").

[Synthesis of [A] Polymer]

[Synthesis Example 1]

43.88 g (50 mol%) of the compound (M-1) and 56.92 g (50 mol%) of the compound (M-7) were dissolved in 200 g of 2-butanone and 4.21 g of AIBN Mol%) was added to prepare a monomer solution. A 1000 mL three-necked flask containing 100 g of 2-butanone was purged with nitrogen for 30 minutes and then heated to 80 DEG C with stirring, and the monomer solution prepared was added dropwise over 3 hours with a dropping funnel. The start of dropwise addition was defined as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was water-cooled and cooled to 30 캜 or lower. The cooling polymerization reaction solution was poured into 2,000 g of methanol, and the precipitated white powder was separated by filtration. The obtained white powder was washed twice with 400 g of methanol, followed by filtration and drying at 50 캜 for 17 hours to obtain a polymer (A-1) in the form of a white powder (73 g, yield 73%). The polymer (A-1) had an Mw of 7,730, a Mw / Mn of 1.51, and a low molecular weight component content of 0.05% by mass. As a result of ¹³ C-NMR analysis, the content ratio of the structural units derived from (M-1) and (M-7) was 47.3 mol% and 52.7 mol%.

[Synthesis Examples 2 to 10]

The procedure of Synthesis Example 1 was repeated, except that the kind and amount of the monomer and the amount of AIBN as a radical polymerization initiator (mole% based on the total amount of the monomers) were changed as shown in Table 1, -2) to (A-10) were synthesized. The yield (%) of the obtained polymer, the content ratio (mol%) of each structural unit, Mw, Mw / Mn and the content of the low molecular weight component (mass%) are shown together in Table 1.

[Synthesis of [F] polymer]

[Synthesis Example 11]

71.07 g (70 mol%) of the compound (M-2) and 28.33 g (30 mol%) of the compound (M-9) were dissolved in 100 g of 2-butanone, 10.35 g of azobisisobutyrate was added to prepare a monomer solution. A 1000 mL three-necked flask containing 100 g of 2-butanone was purged with nitrogen for 30 minutes and then heated to 80 DEG C with stirring, and the monomer solution prepared was added dropwise over 3 hours with a dropping funnel. The start of dropwise addition was defined as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was water-cooled and cooled to 30 캜 or lower. The resulting polymerization reaction solution was transferred to a 4 L separatory funnel, and then the polymerization reaction solution was homogeneously diluted with 300 g of n-hexane and 1,200 g of methanol was added thereto. Subsequently, 60 g of distilled water was added, stirred again, and allowed to stand for 30 minutes. Subsequently, the lower layer was recovered and solvent substitution was carried out to obtain a propylene glycol monomethyl ether acetate solution of the polymer (F-1) (yield: 60%). The polymer (F-1) had an Mw of 7,200, an Mw / Mn of 2.00, and a low molecular weight component content of 0.07% by mass. As a result of ¹³ C-NMR analysis, the content ratio of the structural units derived from (M-2) and (M-9) was 71.1 mol% and 28.9 mol%, respectively.

&Lt; Preparation of radiation-sensitive resin composition >

The components used in the preparation of the radiation sensitive resin composition are shown below.

[Component [B]]

The structural formula is shown below.

B-1: diphenyl iodonium nonafluoro-n-butanesulfonate

B-2: 4-cyclohexylsulfonylphenyldiphenylsulfonium 4- [2- (norbornanactone-2-yloxycarbonyl) cyclohexan-1-ylcarbonyloxy] -1,1,2- Trifluorobutane-1-sulfonate

[[C] sensitizer precursor]

C-1: Bis (4-methoxyphenyl) methanol

This sensitizer precursor (C-1) is converted into 4,4'-dimethoxybenzophenone (hereinafter also referred to as "sensitizer (C-1 ')") which is sensitized by the action of an acid.

Further, a cyclohexane solution of 0.0001% by mass was prepared for each of the sensitizer precursor (C-1) and the sensitizer (C-1 ') and the absorbance of these measurement solutions was measured by using spectrophotometer (V-670, manufactured by Nihon Bunko Co., Ltd.). At the wavelength of 320 nm, the absorbance of the reference solvent was subtracted from the absorbance of the measurement solution, and the absorbance due to the sensitizer precursor (C-1) and the sensitizer (C-1 ') was obtained. As a result, it was confirmed that the absorbance of the sensitizer (C-1 ') was 5 times or more the absorbance of the sensitizer precursor (C-1). It was also confirmed that the transmittance of the cyclohexane solvent used for measuring the absorbance was 95% or more at a wavelength of 320 nm.

[[D] Quanta]

The structural formula is shown below.

D-1: 4-Hydroxy-N-t-amyloxycarbonylpiperidine

D-2: Triphenylsulfonium salicylate

D-3: Triphenylsulfonium 10-camsulfonate

D-4: Triphenylsulfonium N-n-butyltrifluoromethylsulfonamide

D-5: 4-Cyclohexylsulfonylphenyldiphenylsulfonium 1,2-di (cyclohexyloxycarbonyl) ethane-1-sulfonate

D-6: 4-Cyclohexylsulfonylphenyldiphenylsulfonium 1,2-di (norbornanactone-2-yloxycarbonyl) ethane-1-sulfonate

[[E] Solvent]

E-1: Propylene glycol monomethyl ether acetate

E-2: Cyclohexanone

E-3:? -Butyrolactone

[Example 1]

, 100 parts by mass of the polymer (A-1) as the component [A], 11 parts by mass of the component (B-1) as the component [B], 5 parts by mass of the component (C- (F-1) as the [F] polymer, 4.5 parts by mass of the polymer (D-2), 3,240 parts by mass of the (E-1) ), And the resulting mixed solution was filtered through a filter having a pore diameter of 0.20 mu m to prepare a chemically amplified radiation-sensitive resin composition (J-1).

[Examples 2 to 16 and Comparative Examples 1 to 16]

(J-2) to (J-16) and (CJ-1) to (CJ-1) were prepared in the same manner as in Example 1, except that each component of the type and content described in Table 2 below was used. (CJ-16).

&Lt; Formation of resist pattern &

[Example 1]

The chemically amplified radiation-sensitive resin composition (J-1) prepared in Example 1 was spin-coated on a silicon wafer in "Clean Track ACT-8" manufactured by Tokyo Electron Co., PB was carried out to form a resist film having an average film thickness of 50 nm. Subsequently, an electron beam was irradiated using a simple electron beam drawing apparatus (&quot; HL800D &quot;, output: 50 KeV, current density: 5.0 amperes / cm 2) manufactured by Hitachi Seisakusho Co., Ltd., and patterning was performed. After irradiation of the electron beam, the following operations (a) and (b) were carried out.

(a) Immediately after irradiation of the electron beam, PEB was carried out in the clean track ACT-8 under the conditions of 110 DEG C and 60 seconds. Subsequently, the resist film was developed by a puddle method at 23 DEG C for 1 minute using butyl acetate, and dried to form a negative resist pattern.

(b) Black light (320 nm) manufactured by Toshiba was used and the entire surface was exposed to ultraviolet light for 10 minutes by using a light source of 1 mW / h in the air. Thereafter, PEB was immediately carried out in the clean track ACT-8 under the conditions of 110 DEG C for 60 seconds. Then, in the clean track ACT-8, using butyl acetate at 23 DEG C for 1 minute, After development, the resist film was dried to form a negative resist pattern.

[Examples 2 to 15 and Comparative Examples 1 to 16]

Resist patterns were formed by the same procedure as in Example 1 except that the radiation sensitive resin composition and developer described in Table 3 were used. Each of the negative resist patterns thus formed was evaluated for sensitivity, nano edge roughness, and film reduction amount shown below. The evaluation results are shown in Table 3.

[Comparative Example 1 ']

A positive resist pattern was formed in the same manner as in Example 1 except that the radiation sensitive resin composition (J-1) was used and a 2.38 mass% aqueous solution of tetramethylammonium hydroxide was used as the developing solution. The resist pattern of Comparative Example 1 'was evaluated for sensitivity and nano-edge roughness. The evaluation results are shown in Table 3 together. In Comparative Example 1 ', however, evaluation of film reduction amount was not performed because it was a positive phenomenon.

[Sensitivity (μC / ㎠)]

An exposure amount for forming a line-and-space pattern 1L1S including a line portion having a line width of 150 nm and a space portion having an interval of 150 nm formed by adjacent line portions with a line width of 1: , And the optimum 9 exposure amounts were set as sensitivity (占 폚 / cm2). A (good) "when the sensitivity is less than 30 (μC / cm 2)," AA (very good) "when the sensitivity is less than 30 Was judged to be "B (bad)".

[Nano edge roughness (nm)]

The line pattern of the line-and-space pattern 1L1S was observed using a high-resolution FEB measuring apparatus ("S-9220" manufactured by Hitachi, Ltd.). Arbitrary 20 points in the substrate were observed and the side surface 2a of the line portion 2 of the resist film formed on the silicon wafer 1 was observed with respect to the observed shape as shown in Figs. The line width at the most prominent part of the unevenness and the difference &Dgr; CD of the designed line width of 150 nm were measured, and the average value of the ΔCD was defined as nano edge roughness (nm). A (good) "and 16.5 (nm) when the nano edge roughness (nm) is 15.0 (nm) or less is" AA (very good) , It is determined that &quot; B (bad) &quot; The irregularities shown in Figs. 10 and 11 are exaggerated in actuality.

[Film reduction amount]

The photoresist composition (J-1) prepared in Production Example 1 was spin-coated on a silicon wafer in "Clean Track ACT-8" manufactured by Tokyo Electron Co., A resist film having a thickness of 50 nm was formed. Subsequently, an electron beam was irradiated using a simple electron beam drawing apparatus (&quot; HL800D &quot;, output: 50 KeV, current density: 5.0 amperes / cm 2, manufactured by Hitachi Seisakusho Co., Ltd.), and the 150 nm line- 2 cm x 2 cm at the center of the wafer was exposed at the optimal exposure amount to be formed. After exposure, PEB was performed at 110 DEG C for 60 seconds. Thereafter, development was carried out at 23 DEG C for 30 seconds by the developer shown in Table 3, followed by drying. The film thickness of the remaining film after completing a series of processes was measured, and the value obtained by subtracting the remaining film thickness from the initial film thickness was regarded as a film reduction amount (unit: nm). For measuring the film thickness, a light interference film thickness measuring device ("Lambda ACE" of Dainippon Screen Co., Ltd.) was used. The values of the obtained film reduction amounts are shown in Table 3 together. A (good) "when the measured film reduction amount was less than 20 nm was evaluated as" B (poor) "when the measured film reduction amount was 20 nm or more.

From the results shown in Table 3, it was revealed that the radiation sensitive resin composition of the examples can form a resist pattern with high sensitivity, small nano-edge roughness, and high resolution. Further, when the Mw of the polymer [A] in the radiation sensitive resin composition is in a predetermined range, it has also become possible to reduce the film reduction amount.

The resist pattern forming method and the chemically amplified radiation sensitive resin composition of the present invention are suitably used in an exposure process for forming a resist pattern on a substrate. According to the resist pattern forming method and the chemically amplified radiation sensitive resin composition of the present invention, the sensitivity of the resist can be improved.

1: substrate
2: Resist pattern
2a: lateral side of the resist pattern
11: substrate
12: resist film
121: exposed part (A)
122: exposed part (B)
21: Exposure light source
22: Exposure light source

Claims (14)

A second component which generates an acid by the action of a first exposure light including radiation of a first wavelength and a second component which generates an acid by the action of the first exposure light, A step of forming a resist film on a substrate by using a chemically amplified radiation sensitive resin composition containing a varying sensitizer precursor,
A first exposure step of exposing the resist film with the first exposure light;
A second exposure step of exposing the resist film exposed with the first exposure light to a second exposure light including radiation having a second wavelength longer than the first wavelength,
A step of developing the resist film exposed with the second exposure light with a developer mainly composed of an organic solvent
And,
Of ^{(I PP) / (I P} ) when in the absorbance (I ^P) in the second wavelength of the sensitized body and the absorbance at the second wavelength of the precursor (I ^PP), the sensitized body Value is 0.2 or less. The method according to claim 1, wherein the first exposure light does not substantially contain a second wavelength of radiation. 3. The method according to claim 1 or 2, wherein the first exposure step is a step of exposing the resist film to one surface, and the second exposure step is a step of exposing a resist film exposed as the first exposure light to a pattern- Pattern formation method. The method according to claim 1 or 2, wherein the first exposure step is a step of exposing the resist film to a pattern, and the second exposure step is a step of exposing a resist film exposed on the first exposure light to one surface, Pattern formation method. The method for forming a resist pattern according to any one of claims 1 to 4, wherein the first component comprises a group which generates a polar group by dissociation of an acid-dissociable group by the action of an acid. The method for forming a resist pattern according to any one of claims 1 to 5, wherein the second component and the sensitizer precursor are components different from the first component. The resist pattern forming method according to claim 6, wherein the content of the second component relative to the total solid content of the chemically amplified radiation sensitive resin composition is 10% by mass or more and 30% by mass or less. The method for forming a resist pattern according to claim 5, wherein the first polymer comprises at least one of the second component and the sensitizer precursor. 9. The method according to any one of claims 5 to 8, wherein the developing solution used in the developing step is an ionic compound, a hydrogen bond, a covalent bond, a coordination bond, a dipole interaction, Wherein the first compound further comprises a first compound which forms a combination. The method for forming a resist pattern according to claim 9, wherein the first compound is a polymer having a nitrogen-containing compound, an onium salt, an onium salt, a basic polymer, a phosphorus compound or a combination thereof. 11. The method according to any one of claims 1 to 10, wherein the first exposure light is extreme ultraviolet light or electron beams. The method according to any one of claims 1 to 11, wherein before the resist film forming step,
Further comprising the step of forming an organic underlying film on the side of the substrate on which the resist film is to be formed. 13. The method according to claim 12, further comprising, between the organic underlying film forming step and the resist film forming step,
And forming a silicon-containing film on a surface of the organic underlying film that forms the resist film. A chemically amplified radiation-sensitive resin composition for use in the method for forming a resist pattern according to any one of claims 1 to 13,
A second component which generates an acid by the action of a first exposure light including radiation of a first wavelength and a second component which generates an acid by the action of the first exposure light, Wherein the radiation sensitive resin composition contains a varying sensitizer precursor.

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