KR20190129992A - Chemically Amplified Resist Materials and Methods of Forming Resist Patterns - Google Patents

Abstract

In the pattern formation technique using radiation having a wavelength of less than 250 nm, such as EUV, electron beam, ion beam, KrF excimer laser, and ArF excimer laser, the object of the present invention is to provide a resist material capable of achieving high sensitivity and excellent lithography characteristics at a high level. do. The present invention is a chemically amplified resist material used as the photosensitive resin composition in a lithography process including a partial irradiation step, a whole surface irradiation step, a heating step, and a developing step. And a base component that is soluble or insoluble in the developer, and (2) a component that generates a radiation sensitive sensitizer and an acid by irradiation with radiation, wherein the component (2) includes the following components (a) and (b) A compound which contains a component, following (b) and (c) component, or all of following (a)-(c) components, and the said (b) component decomposes by the action of an acid, and is represented by following formula (A) It is a chemically amplified resist material containing a precursor for generating a.

Description

Chemically Amplified Resist Materials and Methods of Forming Resist Patterns

The present invention relates to a chemically amplified resist material and a method of forming a resist pattern.

As one of the element technologies for manufacturing next-generation semiconductor devices, EUV (extreme ultraviolet light) lithography has attracted attention. EUV lithography is a pattern formation technique using EUV light having a wavelength of 13.5 nm as an exposure light source. According to EUV lithography, in the exposure process of the semiconductor device manufacturing process, it is demonstrated that a very fine resist pattern (for example, 20 nm or less) can be formed.

However, since the EUV light source currently developed has low output, it requires a long time for exposure processing, and as a result, EUV lithography has not come to practical use. In order to supplement the low output of an EUV light source, it is thought that the sensitivity of a resist material (photosensitive resin composition) is improved (refer patent document 1). Problems similar to those of EUV also exist in the output and sensitivity of lithography using electron beams, ion beams, and the like as light sources.

Japanese Patent Publication No. 2002-174894

However, it has been difficult in the prior art to achieve both high sensitivity and excellent lithography characteristics (high resolution, low pattern roughness, etc.) at a higher level. If the sensitivity can be improved while maintaining excellent lithography characteristics, the number of pulses of the laser can be reduced not only in lithography using EUV, electron beam and ion beam as a light source, but also in lithography using KrF excimer laser light or ArF excimer laser light as a light source. Thus, maintenance cost can be reduced. Therefore, in the pattern formation technique using radiation having a wavelength of 250 nm or less, such as an EUV, an electron beam, an ion beam, a KrF excimer laser, an ArF excimer laser, etc., a resist capable of achieving both high sensitivity and excellent lithography characteristics at a high level can be achieved. It is an object to provide a material. Moreover, an object of this invention is to provide the resist pattern formation method using the said resist material.

Invention made in order to solve the said subject is 250 degree | times in the process of irradiating the 1st radiation which has a wavelength of 250 nm or less to a part of resist film formed using the photosensitive resin composition, and the whole surface of the resist film after the said partial irradiation process. A lithographic process comprising the step of irradiating a second radiation having a wavelength exceeding nm, the step of heating the resist film after the whole surface irradiation step, and the step of developing the resist film after the heating step with a developer. A chemically amplified resist material used as a photosensitive resin composition, comprising: (1) a base component that is soluble or insoluble in the developer by the action of an acid; and (2) a radiation sensitive sensitizer and an acid generated by irradiation. A component, wherein the component (2) contains the following components (a) and (b), (b) and (c) components, or (a) (C) a chemically amplified resist material containing a precursor containing both the component and generate the compound wherein the (b) component, which is decomposed by the action of an acid is represented by the following formula (A).

(a) In the non-irradiation part which generate | occur | produces an acid and the radiation sensitive sensitizer which absorbs the said 2nd radiation by irradiation of the said 1st radiation, and the 1st radiation is not irradiated in the said some irradiation process, 2nd radiation A radiation-sensitive acid-sensitizer generator in which the acid and the radiation-sensitive sensitizer are substantially not generated by irradiation of

(b) In the non-irradiation part which generate | occur | produces the radiation sensitive sensitizer which absorbs a 2nd radiation by the said 1st irradiation, and in which the 1st radiation is not irradiated in the said partial irradiation process, it irradiates for 2nd radiation A radiation sensitive sensitizer generator in which said radiation sensitive sensitizer is not substantially generated by

(c) Radiation radiation which does not generate | occur | produce substantially the said acid by irradiation of a 2nd radiation in the non-irradiation part which generate | occur | produces an acid by irradiation of the said 1st radiation and in which the 1st radiation is not irradiated in the said partial irradiation process. Acid generator

(In formula (A), R ^a to R ^d are each independently a hydrogen atom, an amino group, a sulfanyl group, a halogen atom or a C 1-20 monovalent organic group, and R ¹ to R ⁶ are each independently hydrogen An atom, a hydroxy group, an amino group, a sulfanyl group, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, or two or more of R ^a to R ^d and R ¹ to R ⁶ join together to form a carbon chain to which they are bonded Is part of a ring structure of reduced water 4 to 20. However, at least one of R ¹ to R ⁶ is a hydroxy group.)

Another invention made in order to solve the said subject contains (1) the base component soluble or insoluble in a developing solution by the action of an acid, and (2) the component which produces | generates a radiation sensitive sensitizer and an acid by irradiation. And the said (2) component contains the said (a) and (b) component, the said (b) and (c) component, or all the said (a)-(c) components, and the said (b) component , A chemically amplified resist material comprising a precursor which decomposes under the action of an acid and generates a compound represented by the above formula (A).

Another invention made to solve the above problems is a step of coating the chemically amplified resist material on a substrate, and a step of irradiating a portion of the resist film formed by the coating step with a radiation having a wavelength of 250 nm or less; And a step of irradiating the entire surface of the resist film after the partial irradiation step with radiation having a wavelength exceeding 250 nm, a step of heating the resist film after the whole surface irradiation step, and a step of developing the resist film after the heating step. It is a resist pattern formation method.

Here, "in the non-irradiation part in which the 1st radiation is not irradiated in the said partial irradiation process, the said acid and a radiation sensitive sensitizer are not substantially generated by irradiation of a 2nd radiation", "1st radiation in the said partial irradiation process In the non-irradiation part which is not irradiated, the said radiation-sensitive sensitizer does not generate | occur | produce substantially by irradiation of a 2nd radiation "" In the non-irradiation part in which the 1st radiation is not irradiated in the said some irradiation process, irradiation of 2nd radiation is carried out The acid and the radiation-sensitive sensitizer are not substantially generated when the second radiation is irradiated without the first radiation. &Quot; " without the first radiation The radiation-sensitive sensitizer is not substantially generated when only the second radiation is irradiated, and the first radiation is not irradiated. And when the second radiation is irradiated only, the acid is not substantially generated. ”An acid or a radiation sensitizer does not occur by irradiation of only the second radiation, or an acid or radiation is irradiated only by the second radiation. Even when a radiation sensitive sensitizer occurs, the non-irradiation part can maintain the difference in the concentration of an acid or a radiation sensitive sensitizer between the irradiation part and the non-irradiation part in some irradiation to the extent which can form a pattern. The amount of generation of acid or radiation-sensitive sensitizer due to the irradiation of the second radiation is small, and as a result, only one of the above-mentioned some irradiation portions or non-some irradiation portions (i.e., portions where no radiation is irradiated during some irradiation) in the developing step. This means that the amount of acid or radiation sensitive sensitizer generated is small enough to dissolve in the developer. An "organic device" means a group containing at least one carbon atom. "Reduced number" means the number of atoms which comprise the ring of an aromatic ring structure, an aromatic heterocyclic structure, an alicyclic structure, and an aliphatic heterocyclic structure, and in the case of a polycyclic ring structure, the number of atoms which comprise this polycyclic is pushed.

According to the present invention, in a pattern forming technique using radiation having a wavelength of 250 nm or less, such as EUV light, electron beam, ion beam, KrF excimer laser, ArF excimer laser, both high sensitivity and excellent lithography characteristics can be achieved at a high level. A chemically amplified resist material is provided. Moreover, according to this invention, the resist pattern formation method using the said resist material is provided.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail. In addition, this invention is not limited to the following embodiment.

<Chemical Amplification Resist Material>

The chemically amplified resist material according to the present embodiment is used as a photosensitive resin composition in a two-stage lithography process. The two-stage exposure lithography process includes a partial irradiation step, a whole surface irradiation step, a heating step, and a developing step. In the said partial irradiation process, the 1st radiation which has a wavelength of 250 nm or less is irradiated. Moreover, in the said whole surface irradiation process, 2nd radiation which has a wavelength exceeding 250 nm is irradiated.

The chemically amplified resist material according to the present embodiment may be either a positive resist material or a negative resist material, and is appropriately selected by selecting a base component, a developer, and the like described later. Here, a resist material in which a part of the irradiation part is eluted due to the phenomenon after partial irradiation and the non-part irradiation part (shielding part) remains is called a positive resist material. On the contrary, a non-irradiation part (shielding part) is eluted and the resist material remaining in the irradiation part is negative. It is called a type registrar.

The chemically amplified resist material (hereinafter, simply referred to as "resist material") according to the present embodiment includes (1) a base component that is soluble or insoluble in a developer by the action of an acid, and (2) radiation irradiation. Radiation-sensitive sensitizers and components that generate acids.

<(1) base component>

In this embodiment, an organic compound may be sufficient as the said (1) base component, and an inorganic compound may be sufficient as it. This organic compound may be a high molecular compound or a low molecular compound. The polymer may be a polymer in which the solubility in a developing solution changes due to the action of an acid. Such polymers are widely used as base components of resist materials. In addition, it is preferable that (1) the base component can realize formation of a resist pattern having a sufficiently high verticality without excessively absorbing the first radiation in partial irradiation. In addition, in (1) base component, it is preferable that absorption of the 2nd radiation in whole surface irradiation is low and it is hard to cause unnecessary sensitization reaction in a non-irradiation part at the time of whole surface irradiation.

As a minimum of the weight average molecular weight (Mw) of the said polymer, 1,000 is preferable, 3,000 are more preferable, and 5,000 are more preferable. As an upper limit of said Mw, 200,000 is preferable, 50,000 is more preferable, 10,000 is further more preferable. As an upper limit of the ratio of Mw with respect to the number average molecular weight (Mn) of the said polymer, 5 is preferable, 3 is more preferable, and 2.2 is still more preferable. As a minimum of the said ratio, it is 1 normally and 1.5 is preferable. In the developing step, part of the irradiation part becomes soluble or insoluble in the developer by the acid catalyzed reaction in the heating step after the whole surface irradiation.

In this specification, Mw and Mn of a polymer are 1.0 mL / min of a flow volume and the elution solvent tetrahydrofuran using a GPC column (two "G2000HXL", one "G3000HXL", and one "G4000HXL" of Tosoh Corporation). It is a value measured by the gel permeation chromatography (GPC) which makes monodisperse polystyrene into a standard using a differential refractometer as a detector on the analysis conditions of 1.0 mass% of sample concentrations, 100 microliters of sample injection amounts, and a column temperature of 40 degreeC.

As a polymer in which the solubility to a developing solution changes by the action of the said acid, the polymer which has a structural unit containing a polar group (for example, an acidic functional group), the polymer which has a structural unit containing an acid dissociable group, etc. are mentioned, for example. Can be. Although the polymer which has a structural unit containing a polar group is soluble in an alkaline developing solution, it becomes insoluble in an alkaline developing solution by reacting by action of an acid and a crosslinking agent mentioned later in a heating process. In this case, in the developing step, the resist film of the non-illuminated portion can be removed by the alkaline developer. Therefore, when developing the resist film formed using the said polymer with alkaline developing solution, the said resist material acts as a negative resist material.

On the other hand, the polymer having a structural unit containing the acid dissociable group is soluble in the organic developer, but insoluble or poorly soluble in the alkaline developer. The polymer having a structural unit containing the acid dissociable group is degraded (deprotected) by the action of an acid in the heating step, and the polarity is imparted, so that it is soluble in an alkaline developer and insoluble in an organic developer. . In this case, the resist film of the non-illumination part can be removed by the organic developer, and part of the irradiation part can be removed by the alkaline developer. Therefore, when developing the resist film formed using the said polymer with an organic developing solution, a resist material functions as a negative resist material. On the other hand, when developing the resist film formed using the said polymer with alkaline developing solution, a resist material functions as a positive resist material.

[Polymer Having Structural Unit Containing Acid Dissociable Group]

A polymer having a structural unit (hereinafter also referred to as "structural unit (I)") containing an acid dissociable group (hereinafter also referred to as "[P] polymer") is a lactone structure and a cyclic carbon other than the structural unit (I). Structural unit (II) containing a carbonate structure, a sultone structure, or a combination thereof, a structural unit (III) including an aromatic ring to which a hydroxy group bonds, and a structural unit (IV) including a group represented by formula (Y) described later ) And may have a structural unit other than the structural units (I) to (IV).

(Structural unit (I))

Structural unit (I) is a structural unit containing an acid dissociable group. As structural unit (I), the structural unit etc. which are represented by following formula (X) are mentioned, for example.

In the formula (X), R ^W is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^X is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^Y and R ^Z are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a part of an alicyclic structure having 3 to 20 reduced water, in which these groups are combined with each other to form together with the carbon atom to which they are bonded.

The "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. This "hydrocarbon group" may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The "chain hydrocarbon group" does not include a cyclic structure but refers to a hydrocarbon group composed of only a chain structure, and includes both a straight chain hydrocarbon group and a branched hydrocarbon group. The "alicyclic hydrocarbon group" refers to a hydrocarbon group containing only an alicyclic structure and not containing an aromatic ring structure as the ring structure, and includes both a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic hydrocarbon group. However, it is not necessary to be comprised only with an alicyclic structure, and the chain structure may be included in one part. An "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be comprised only with an aromatic ring structure, and the chain structure and alicyclic structure may be included in one part.

As R ^W , a hydrogen atom and a methyl group are preferable, and a methyl group is more preferable.

R ^X, as the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^Y and R ^Z, having 1 to 20 monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, having a carbon number of 6 to 20 of Monovalent aromatic hydrocarbon group etc. are mentioned.

As a C1-C20 monovalent chain hydrocarbon group, For example, Alkenyl groups, such as an alkyl group, such as a methyl group, an ethyl group, n-propyl group, an i-propyl group, an ethenyl group, a propenyl group, butenyl group, an ethynyl group, and a propynyl group And alkynyl groups such as butynyl group and the like.

As a C3-C20 monovalent alicyclic hydrocarbon group, Monocyclic alicyclic unsaturated-hydrocarbon groups, such as monocyclic alicyclic saturated hydrocarbon groups, such as a cyclopentyl group and a cyclohexyl group, a cyclopentenyl group, and a cyclohexenyl group, for example And polycyclic alicyclic unsaturated hydrocarbon groups such as polycyclic alicyclic saturated hydrocarbon groups such as norbornyl group, adamantyl group, and tricyclodecyl group, norborneneyl group, and tricyclodecenyl group.

As a C6-C20 monovalent aromatic hydrocarbon group, For example, aryl groups, such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, an anthryl group, a benzyl group, a phenethyl group, a naphthyl methyl group, an anthryl methyl group, etc. Aralkyl group etc. are mentioned.

Examples of the alicyclic structure of reduced water 3 to 20 in which R ^Y and R ^Z join together and constituted with the carbon atoms to which they are bonded include, for example, a cyclopentane structure, a cyclohexane structure, a norbornane structure, and an adamantane structure. have.

As the structural unit (I), a structural unit derived from 1-alkyl cycloalkan-1-yl (meth) acrylate is preferable.

As a minimum of the content rate of a structural unit (I), 20 mol% is preferable with respect to all the structural units which comprise a [P] polymer, and 40 mol% is more preferable. As an upper limit of the said content rate, 80 mol% is preferable and 60 mol% is more preferable.

(Structural Unit (II))

Structural unit (II) is a structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof. If the polymer [P] has a structural unit (II), the solubility in a developing solution can be made more suitable.

As structural unit (II), the structural unit derived from butyrolactone-yl (meth) acrylate, the structural unit derived from norbornane lactone-yl (meth) acrylate, for example, ethylene carbonate-ylmethyl The structural unit derived from (meth) acrylate, the structural unit derived from norbornane sultone-yl (meth) acrylate, etc. are mentioned.

When the polymer [P] has a structural unit (II), the lower limit of the content ratio of the structural unit (II) is preferably 20 mol%, more preferably 30 mol%. As an upper limit of the said content rate, 80 mol% is preferable and 70 mol% is more preferable.

(Structural Unit (III))

Structural unit (III) is a structural unit containing the aromatic ring which a hydroxyl group couple | bonds. When the polymer [P] has a structural unit (III), the sensitivity in partial irradiation of the resist material can be further improved.

As structural unit (III), the structural unit derived from hydroxy styrene, the structural unit derived from hydroxy vinyl naphthalene, the structural unit derived from hydroxyphenyl (meth) acrylate, etc. are mentioned, for example.

When the polymer [P] has a structural unit (III), the lower limit of the content ratio of the structural unit (III) is preferably 20 mol%, more preferably 30 mol%. As an upper limit of the said content rate, 80 mol% is preferable and 70 mol% is more preferable.

(Structural unit (IV))

Structural unit (IV) is a structural unit containing the group represented by following formula (Y). When the polymer [P] has a structural unit (IV), the sensitivity in partial irradiation of the resist material can be further improved.

In said formula (Y), R <^P> and R <^Q> are respectively independently a fluorine atom or a C1-C10 fluorinated alkyl group.

Examples of the fluorinated alkyl group having 1 to 10 carbon atoms represented by R ^P and R ^Q include, for example, a fluoromethyl group, difluoromethyl group, trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, and nonafluorobutyl group. Etc. can be mentioned. Of these, trifluoromethyl group is preferable.

When the polymer [P] has a structural unit (IV), the lower limit of the content ratio of the structural unit (IV) is preferably 5 mol%, more preferably 10 mol%. As an upper limit of the said content rate, 50 mol% is preferable and 30 mol% is more preferable.

As a minimum molecular weight of the said low molecular weight compound, 300 is preferable and 500 is more preferable. As an upper limit of the said molecular weight, 3,000 are preferable and 2,000 are more preferable. As for the said low molecular weight compound, some irradiation part becomes soluble or insoluble in a developing solution in an image development process by the acid catalyst reaction in the heating process after whole surface irradiation.

As a low molecular weight compound, shaping | molding molecule | numerators, such as a trucesen derivative, a calix arene derivative, Noria, a dendrimer, etc. are mentioned, for example.

As an inorganic compound, organic metal compounds, such as metal oxides, such as a cobalt oxide, a hafnium oxide, a zirconium oxide, and a complex, are mentioned, for example. The metal oxide may be particulate or may be nanoparticles having a particle diameter of nano order. The particles of the metal oxide may be coordinated with carboxylic acid or the like. (1) An example of the solubility change at the time of using an inorganic compound as a base component is shown below. For example, (1) When nanoparticles of a metal oxide in which carboxylic acid is coordinated are used as the base component, the anion of the acid generated by irradiation is coordinated with the metal oxide in place of the carboxylic acid anion. Thereby, since the interaction of metal oxide particles increases, (1) base component gelatinizes and dissolution of an irradiation part in the case of dissolving only a non-irradiation part in a image development process can be suppressed.

<(2) Components that Generate Radiation Sensitizers and Acids by Irradiation>

The said component is a component which generate | occur | produces a radiation sensitive sensitizer and an acid by irradiation (exposure). The said component is (a) component, (a) of three components of (a) a radiation sensitive acid-sensitizer, (b) a radiation sensitive sensitizer, and (c) a radiation sensitive acid generator Any two of the components) to (c) or both of the components (a) to (c). That is, in the resist material, the component (2) is blended with the base component (1). The (a) radiation-sensitive acid-sensitizer generator, (b) radiation-sensitive sensitizer generator, and (c) the radiation-sensitive acid generator may be a low molecular compound, and a group which generates an acid and a sensitizer. The polymer which has, the polymer which has a group which produces a sensitizer, or the polymer which has a group which produces an acid may be sufficient.

[(a) Radiation-sensitive acid-sensitizer generator]

(a) The radiation-sensitive acid-sensitizer generator generates, by irradiation of the first radiation, a radiation-sensitive sensitizer which absorbs the acid and the second radiation, and the first radiation is irradiated in the partial irradiation step. In the non-irradiation part not provided, the acid and the radiation-sensitive sensitizer are substantially not generated by the irradiation of the second radiation. Since the said (a) radiation sensitive acid-sensitizer generator has the said characteristic, generation | occurrence | production of the said acid and a radiation sensitive sensitizer by irradiation of the 2nd radiation in a whole surface irradiation process can be suppressed.

In addition, (a) when acid and a radiation sensitive sensitizer generate | occur | produced by irradiating a radiation sensitive acid-sensitizer generating agent with a 2nd radiation, acid and radiation sensitivity between an irradiation part and a non-irradiation part in some irradiation. The amount of acid and radiation-sensitive sensitizer produced by the irradiation of the second radiation can be reduced to such an extent that the difference in the concentration of the sensitizer can be maintained at a magnitude capable of forming a pattern. As a minimum of the wavelength of a 2nd radiation, 300 nm is preferable, 320 nm is more preferable, 350 nm is still more preferable. (a) When a radiation-sensitive acid-sensitizer generator generates an acid and a radiation-sensitive sensitizer by irradiation of a 2nd radiation, the 1st radiation is irradiated by making the wavelength of 2nd radiation more than the said minimum. In some irradiation parts, acid is generated at the time of irradiation of the second radiation by the sensitizing action of the radiation-sensitive sensitizer generated. On the contrary, in some non-irradiation parts in which the first radiation is not irradiated, acid is generated at the time of irradiation of the second radiation. This is suppressed. As a result, the sensitivity and contrast between some irradiating portions and non-illuminating portions can be improved.

(a) As a radiation sensitive acid-sensitizer generator, an onium salt compound, a diazomethane compound, a sulfonimide compound, etc. are mentioned. Moreover, as an onium salt compound, a sulfonium salt compound, a tetrahydrothiophenium salt compound, an iodonium salt compound, etc. are mentioned, for example. As a (a) radiation-sensitive acid-sensitizer which is a sulfonium salt compound, the compound etc. which have a carbon atom adjacent to S <^+> , and the hydroxy group couple | bonded with this carbon atom are mentioned.

[(b) Radiation Sensitizers]

(b) The radiation-sensitive sensitizer generator is a non-irradiation part that generates a radiation-sensitive sensitizer that absorbs the second radiation by irradiation of the first radiation and is not irradiated with the first radiation in the partial irradiation step. Is a component in which the radiation-sensitive sensitizer is not substantially generated by the irradiation of the second radiation, and is different from the radiation-sensitive acid-sensitizer (a). In the pattern formation method according to the present embodiment, in some irradiation steps, (b) the chemical structure of the radiation-sensitive sensitizer generating agent is converted by direct or indirect reaction and assists acid generation in the whole surface irradiation step. To produce a radiosensitizer; By shifting the peak of the wavelength of the absorbed radiation before and after part of the irradiation step, the absorption contrast of the second radiation in the whole surface irradiation step is easily obtained between the irradiation part and the non-irradiation part in which the radiation sensitive sensitizer is generated. Moreover, when the peak shift of the said absorption wavelength is large, the absorption contrast of 2nd radiation in a whole surface irradiation process becomes large.

Moreover, (b) the difference of the density | concentration of the radiation sensitive sensitizer between the irradiation part and non-irradiation part in some irradiation, when a radiation sensitive sensitizer generate | occur | produced by irradiating a radiation sensitive sensitizer generating agent with a 2nd radiation. 300 nm is preferable and 320 nm is more preferable as a lower limit of the wavelength of the 2nd radiation which can reduce the generation | occurrence | production amount of the radiation sensitive sensitizer by irradiation of a 2nd radiation so that it can hold | maintain to the magnitude | size of the grade which can form a pattern. Preferably, 350 nm is more preferable. (b) When the radiation sensitive sensitizer generating agent produces a radiation sensitive sensitizer by irradiation of a 2nd radiation, in some irradiation part to which 1st radiation is irradiated by making wavelength of 2nd radiation more than the said minimum, Due to the sensitizing action of the radiation-sensitive sensitizer generated, acid is generated when the second radiation is irradiated. On the contrary, in some non-irradiating portions in which the first radiation is not irradiated, acid is suppressed when the second radiation is irradiated. . As a result, the sensitivity and contrast between some irradiating portions and non-illuminating portions can be improved.

(b) As a radiation sensitive sensitizer, what becomes a compound (carbonyl compound) which has a carbonyl group which absorbs the 2nd radiation in a whole surface irradiation process by irradiation of the 1st radiation in some irradiation processes. desirable. Examples of the carbonyl compound include aldehydes, ketones, carboxylic acids and carboxylic acid esters. By the said reaction, only the (b) radiation sensitive sensitizer of a part of irradiation part shifts the peak of the absorption wavelength of a radiation. Therefore, after partial irradiation, when whole surface irradiation is carried out with the radiation of the wavelength which can absorb only a part of irradiation part, only a part of irradiation part can be selectively increased or decreased.

Said (b) radiation sensitive sensitizer generator decomposes by the action of an acid, and generate | occur | produces the compound represented by following formula (A) (henceforth "(A) sensitizer") (Hereafter, " And (B) precursor). (b) the action of an acid generated from (a) a radiation-sensitive acid-sensitizer or (c) a radiation-sensitive acid generator, in some irradiating portions, since the radiation-sensitive sensitizer contains the precursor [B]. By this, a radiation sensitive sensitizer can be efficiently generated, and a favorable fine pattern can be formed.

((A) sensitizer)

(A) A sensitizer is a compound represented by following formula (A).

In said formula (A), R ^<a> -R <^d> is respectively independently a hydrogen atom, an amino group, a sulfanyl group, a halogen atom, or a C1-C20 monovalent organic group, R <^1> -R <^6> is respectively independently hydrogen An atom, a hydroxy group, an amino group, a sulfanyl group, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, or two or more of R ^a to R ^d and R ¹ to R ⁶ join together to form a carbon chain to which they are bonded It is a part of ring structure of reducing water 4-20 to become. Provided that at least one of R ¹ to R ⁶ is a hydroxy group.

As ^a C1-C20 monovalent organic group represented by R ^<a> -R <^d> and R <^1> -R <^6> , it is a C1-C20 monovalent hydrocarbon group, for example, a bivalent hetero atom between carbon-carbon of this hydrocarbon group. The group etc. which substituted one part or all part of the hydrogen atom which the group ((alpha)) containing a containing group, the said monovalent hydrocarbon group, and group ((alpha)) have by the monovalent hetero atom containing group are mentioned.

As the monovalent hydrocarbon group having 1 to 20 carbon atoms, for example, in the same group, and the like of those exemplified as the above formula (X) R ^X, R ^Y, and having 1 to 20 carbon monovalent hydrocarbon group of R ^Z group in the Can be.

As a hetero atom which comprises monovalent and bivalent hetero atom containing group, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, a halogen atom, etc. are mentioned, for example. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned.

As a bivalent hetero atom containing group, -O-, -CO-, -S-, -CS-, -NR'-, the group which combined two or more of these, etc. are mentioned, for example. R 'is a hydrogen atom or a monovalent hydrocarbon group.

As a monovalent hetero atom containing group, halogen atoms, such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxyl group, a carboxy group, a cyano group, an amino group, a sulfanyl group, etc. are mentioned, for example.

As ^a ring structure of the reduced water 4-20 which two or more of R ^<a> -R <^d> and R <^1> -R <^6> combine with each other and comprise with the carbon chain to which they couple | bond, for example, a naphthalene structure, an anthracene structure, a fluorene structure, a di, Heterocyclic structures, such as a carbocyclic structure, such as a benzocyclohexane structure, a xanthene structure, a thioxanthene structure, a dibenzothiacyclohexane structure, and a dibenzoaza cyclohexane structure, etc. are mentioned.

(A) As a sensitizer, it is preferable that R <^2> of said Formula (A) is a hydroxyl group. (A) A sensitizer will improve sensitization performance more if R <^2> is a hydroxyl group, and the sensitivity of the said resist material will improve more.

(A) As a sensitizer, it is preferable that at least 2 of R <^1> -R <^6> of said Formula (A) is a hydroxyl group. (A) A sensitizer will improve a sensitization performance more if two or more of R <^1> -R <^6> is a hydroxyl group, and the sensitivity of the said resist material will improve more.

(A) As a number of the hydroxyl group couple | bonded with the aromatic ring which a sensitizer has, 1-3 are preferable, 1 and 2 are more preferable, and 2 is still more preferable.

Moreover, it is preferable that a hydroxyl group does not couple | bond with the carbon atom (carbon atom of an ortho position) on the same aromatic ring adjacent to the carbon on the aromatic ring to which the carbonyl group of (A) sensitizer is couple | bonded. This reason is explained below.

A sensitizer transitions from a singlet state to a singlet state here by irradiation of a 2nd radiation. However, the singlet state here has a very short life span and is in nanosecond units, and the probability of donating energy or electrons to a photoacid generator or the like from the singlet state is very low.

On the other hand, if the sensitizer can transition from the singlet state here to the triplet state by a behavior called intercross, the lifetime of this triplet state is relatively long and is in microseconds. The probability of donating an electron is greatly improved.

It is known that this intersecting crossover easily occurs between excitation states having different transition characteristics, and since benzophenone has an n-orbit excitation state and an excitation triplet state is an π * orbit, the transition is n-π * transition. Intersecting is very likely (El-Sayed's law). For this reason, benzophenone functions as a good sensitizer, as is generally known.

However, in the benzophenone derivative, when the hydroxyl group is bonded to a carbon atom (ortho-carbon atom in the ortho position) on the same aromatic ring adjacent to the carbon on the aromatic ring to which the carbonyl group is bonded, the energy level of the n orbit is lowered, Since the singlet state here becomes π orbit, and therefore, the transition from the singlet state here to the triplet state becomes π-π * transition, it is difficult for crossover between terms to occur, and thus it is difficult to function as a sensitizer. Becomes.

Examples of the sensitizer (A) include compounds represented by the following formulas (i-1) to (i-24) (hereinafter also referred to as "compounds (i-1) to (i-24)") and the like. Can be.

(A) As a sensitizer, compounds (i-1)-(i-6) are preferable and compound (i-1) and (i-2) are more preferable.

([B] precursor)

A precursor (B) is a compound which decomposes by the action of an acid, and produces (A) a compound. Examples of the precursor (B) include esterified compounds of (A) compounds, acetalized compounds, and the like, and acetalized compounds of (A) compounds are preferable. When the precursor (B) is an acetalide, decomposition due to the action of an acid is more likely to occur, and as a result, the sensitivity of the resist material is further improved.

As esterified compound (A), the compound etc. which substituted the hydrogen atom of the hydroxyl group couple | bonded with the benzene ring with the acyl group, etc. are mentioned, for example.

As the acetalide of the compound (A), for example, a compound obtained by acetalizing a keto group, a compound having an acetal structure derived from two hydroxyl groups located at the ortho position of the benzene ring, and two hydroxyl groups bonded to the aromatic ring of another molecule The compound which has an acetal structure derived from these, etc. are mentioned. Among them, from the viewpoint of ease of synthesis of acetalide, compounds having acetal structures derived from two hydroxy groups located at the ortho position of the benzene ring, compounds having acetalized from the keto group, and structures having the acetalized keto group and the benzene ring Preferred are compounds having both acetal structures derived from two hydroxy groups located at the ortho position.

Examples of the precursor [B] include compounds represented by the following formulas (B-1) to (B-4) (hereinafter also referred to as "compounds (B-1) to (B-4)") and the like. have.

R ^a to R ^d are each independently a hydrogen atom, an amino group, a sulfanyl group, a halogen atom or a C 1-20 monovalent organic group in the formulas (B-1) to (B-4), and R ¹ to Each R ⁶ is independently a hydrogen atom, a hydroxyl group, an amino group, a sulfanyl group, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, or two or more of R ^a to R ^d and R ¹ to R ⁶ are combined with each other; It is a part of ring structure of reduced water 4-20 comprised with the carbon chain which these couple | bond. R ^A and R ^B are each independently a monovalent organic group having 1 to 20 carbon atoms, or a part of a ring structure having 4 to 20 reduced water, in which these groups are combined with each other to form an OCO to which they are bonded. R ^C and R ^D are each independently a monovalent organic group having 1 to 20 carbon atoms or a part of a ring structure having 3 to 20 reduced water where these groups are combined with each other to form together with the carbon atom to which they are bonded.

The formula (B-1) to (B-4) of R ^a to R ^d, and R ¹ to a group represented by R ⁶ and in the formula (A) As the ring structure to those of the group configuration R ^a to R ^d And the same thing as what was illustrated as group and ring structure represented by R <^1> -R <^6> is mentioned.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ^A and R ^B and R ^C and R ^D include, for example, R ^a to R ^d and R ¹ to R ⁶ in the formula (A). The same groups as those exemplified as monovalent organic groups may be mentioned.

As R ^<A> and R <^B> , a linear hydrocarbon group is preferable, an alkyl group is more preferable, and a methyl group is further more preferable.

Examples of the ring structure of reduced water 4 to 20 in which the groups of R ^A and R ^B join together to form an OCO to which they are bonded include a 1,3-dioxacyclopentane structure, a 1,3-dioxacyclohexane structure, and the like. 1,3-dioxacycloalkane structure etc. are mentioned. Of these, 1,3-dioxacyclopentane structure is preferable.

As R <^C> and R <^D> , a linear hydrocarbon group is preferable, an alkyl group is more preferable, and a methyl group is further more preferable.

Examples of the ring structure of reduced water 3 to 20 in which the groups of R ^C and R ^D are combined with each other to form a carbon atom to which they are bonded include a cycloalkane structure such as a cyclopentane structure and a cyclohexane structure.

As the [B] precursor, for example, a compound represented by the following formula (B-1-a), (B-2-a), (B-3-a), (B-4-a) (hereinafter, “ Compound (B-1-a), (B-2-a), (B-3-a), (B-4-a) ", etc. are mentioned.

Among these, compounds (B-1-a), (B-2-a) and (B-4-a) are preferable.

(Synthesis method of [B] precursor)

Precursor (B) can be synthesize | combined by performing acetalization, esterification, etc. using the hydroxyl group couple | bonded with the keto group and / or aromatic ring of (A) sensitizer.

(A) As an acetalizing agent (1a) for converting the keto group of a sensitizer into linear acetal structures, such as a dimethyl acetal structure, For example, trialkyl ortho formate, trimethyl ortho acetate, such as trimethyl ortho formate and triethyl ortho formate, Ortho esters, such as ortho acetate trialkyl, such as ortho acetate, and the like. (A) As an acetalizing agent (1b) for converting the keto group of a sensitizer into cyclic acetal structures, such as a 1, 3- dioxacyclopentane structure, Ortho ester, such as a mixture of trimethyl ortho formate and ethylene glycol, for example, and And mixtures of vicinal diols.

(A) As acetalizing agent (2) for converting two hydroxy groups located at the benzene ring ortho position of the sensitizer into an acetal structure, for example, 2,2-dimethoxypropane, 2,2-diethoxypropane, 3 And ketone acetals having 1 to 20 carbon atoms such as, 3-dimethoxypentane and 1,1-dimethoxycyclohexane.

Compounds (B-1) and (B-4) are acetals in the presence of an acid such as p-toluenesulfonic acid using (A) sensitizer, for example, using acetalizing agent (1a) and / or (1b). It can synthesize | combine by performing a oxidization reaction.

Compound (B-2) is acetal in presence of acids, such as p-toluenesulfonic acid, using the acetalizing agent (2), with respect to the (A) sensitizer which has two hydroxyl groups located in the ortho position of a benzene ring, for example. It can synthesize | combine by performing a oxidization reaction.

Compound (B-3) uses acetalizing agent (1a) and / or (1b) and acetalizing agent (2) with respect to (A) sensitizer having two hydroxyl groups located at the ortho position of the benzene ring, It can synthesize | combine by performing acetalization reaction in presence of acid, such as p-toluenesulfonic acid.

In the acetalization reaction, a solvent such as toluene may be used. Compounds (B-1) to (B-4) can be isolated by appropriately purifying the obtained product by column chromatography, recrystallization, distillation or the like. [B] precursor other than the above can also be synthesize | combined by the said similar method.

[(c) radiation-sensitive acid generator]

(c) In the non-irradiation part in which a radiation sensitive acid generator generates an acid by irradiation of a 1st radiation and in which the 1st radiation is not irradiated in the said partial irradiation process, the said acid is irradiated by 2nd radiation. It is a component which does not generate | occur | produce substantially, and is different from said (a) radiation-sensitive acid-sensitizer generator. (c) Since the radiation-sensitive acid generator has the above properties, it is possible to generate acid only by a part of the irradiation part of the resist film by a radiation sensitization reaction in the whole surface irradiation.

(C) In the case where acid is generated by irradiating the radiation-sensitive acid generator with the second radiation, the difference in the concentration of acid between the irradiated portion and the non-irradiated portion in some irradiation is maintained at a magnitude capable of forming a pattern. As a minimum, 300 nm is preferable, 320 nm is more preferable, and 350 nm is more preferable as a minimum of the wavelength of the 2nd radiation which can reduce the generation | occurrence | production amount of the acid by 2nd radiation irradiation to the extent possible. (c) The radiation-sensitive increase or decrease generated in some irradiation units irradiated with the first radiation by setting the wavelength of the second radiation when the radiation-sensitive acid generator generates acid by irradiation of the second radiation is equal to or greater than the lower limit. The acid is generated when the second radiation is irradiated by the sensitizing action of the sieve, and on the contrary, in some non-irradiating parts to which the first radiation is not irradiated, generation of acid during the irradiation of the second radiation is suppressed. As a result, the sensitivity and contrast between some irradiating portions and non-illuminating portions can be improved.

(c) As a radiation sensitive acid generator, an onium salt compound, a diazomethane compound, an N-sulfonyloxyimide compound, etc. are mentioned, for example. Moreover, as an onium salt compound, a sulfonium salt compound, a tetrahydrothiophenium salt compound, an iodonium salt compound, etc. are mentioned, for example. (c) As a radiation sensitive acid generator, a sulfonium salt compound, an iodonium salt compound, sulfonyl diazomethane, N-sulfonyloxyimide, and an oxime-O-sulfonate type radiation sensitive acid generator are preferable, and a sulfo More preferred are the nium salt compound and the iodonium salt compound.

Examples of the sulfonium salt compound include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, and triphenylsulfonium 2-bicyclo [2.2.1] hept-2- 1-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro- n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulphate Phenyl phenyl diphenyl sulfonium 1, 2- di (cyclohexyloxycarbonyl) ethane-1- sulfonate etc. are mentioned.

As a tetrahydrothiophenium salt compound, it is 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalene-1, for example. -Yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, etc. are mentioned.

As an iodonium salt compound, it is diphenyl iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl- 1, 1,2,2-tetrafluoroethanesulfonate etc. are mentioned.

Examples of the N-sulfonyloxyimide compound include N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxyimide and N- (nonnafluoro -n-butanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxyimide and the like.

As a diazomethane compound, bis (n-propylsulfonyl) diazomethane, bis (isopropyl sulfonyl) diazomethane, etc. are mentioned, for example.

<Optional ingredient>

The resist material of this embodiment may contain [D] acid diffusion control body, [E] solvent, a crosslinking agent, etc. as an arbitrary component other than the above-mentioned (1) base component and (2) component.

[[D] Acid Diffusion Controls]

The acid diffusion controller (D) controls diffusion phenomenon in an acid resist film generated from (a) a radiation-sensitive acid-sensitizer, (c) a radiation-sensitive acid generator, etc. by radiation irradiation. It is a substance which suppresses undesirable chemical reaction in a non-irradiation part. As a containing form in the said resist material of the [D] acid diffusion control body, the form of a glass compound (henceforth also called "[D] acid diffusion control agent" suitably) may be sufficient, and the form incorporated as a part of a polymer may be sufficient as it. It may be a form of both of these.

Examples of the acid diffusion control agent (D) include a nitrogen atom-containing compound, a photodegradable base that is sensitive to radiation and generates a weak acid.

As a nitrogen atom containing compound, an amine compound, an amide group containing compound, a urea compound, a nitrogen containing heterocyclic compound, etc. are mentioned, for example.

Examples of the photodegradable bases include triphenylsulfonium salts of carboxylic acids and the like, and triphenylsulfonium adamantan-1-yloxalate is preferable.

[[E] solvent]

The solvent (E) is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the component (1), the component (2) and optional components contained as desired.

Examples of the solvent (E) include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents, and the like.

As an alcoholic solvent, For example, C3-C18 alicyclic monoalcohol solvent, such as C1-C18 aliphatic monoalcohol solvents, such as 4-methyl- 2-pentanol and n-hexanol, and cyclohexanol And polyhydric alcohol solvents having 2 to 18 carbon atoms such as 1,2-propylene glycol, polyhydric alcohol partial ether solvents having 3 to 19 carbon atoms such as propylene glycol monomethyl ether and the like.

Examples of the ether solvent include dialkyl ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, diisoamyl ether, dihexyl ether and diheptyl ether, tetrahydrofuran and tetrahydro. Aromatic ring containing ether solvents, such as cyclic ether solvents, such as a pyran, diphenyl ether, and anisole, etc. are mentioned.

Examples of the ketone solvents include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone, and ethyl-n-butyl ketone Linear ketone solvents such as methyl-n-hexyl ketone, di-iso-butyl ketone, trimethyl nonanone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and methylcyclohexanone A solvent, 2, 4- pentanedione, acetonyl acetone, acetophenone etc. are mentioned.

As the amide solvent, for example, cyclic amide solvents such as N, N'-dimethylimidazolidinone and N-methylpyrrolidone, N-methylformamide, N, N-dimethylformamide, N, N- And chain amide solvents such as diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, and N-methylpropionamide.

Examples of the ester solvents include monocarboxylic acid ester solvents such as n-butyl acetate and ethyl lactate, polyhydric alcohol carboxylate solvents such as propylene glycol acetate, and polyhydric alcohol partial ethers such as propylene glycol monomethyl ether. Polycarboxylic acid diester solvents, such as a carboxylate solvent and diethyl oxalate, carbonate solvents, such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate, (gamma) -buty Lactone solvents, such as a rock lactone and (delta) -valerolactone, etc. are mentioned.

As a hydrocarbon solvent, C6-C16 aliphatic hydrocarbon solvents, such as n-pentane and n-hexane, C6-C16 aromatic hydrocarbon solvents, such as toluene and xylene, etc. are mentioned, for example.

Of these, ester solvents and ketone solvents are preferable, polyhydric alcohol partial ether carboxylate solvents and cyclic ketone solvents are more preferable, and propylene glycol monomethyl ether acetate and cyclohexanone are more preferable. The radiation sensitive resin composition may contain one kind or two or more kinds of the solvent [E].

[Bridge]

The crosslinking agent is for causing the crosslinking reaction between the base components by the acid catalyst reaction in the heating step after the whole surface irradiation, increasing the molecular weight of the base component, and insolubilizing the developer, and the (1) base component It is different. Since the resist material contains a crosslinking agent, the polar portion becomes non-polarized at the same time as the crosslinking and insoluble in the developer, so that a negative resist material can be provided.

Crosslinkers are compounds having two or more functional groups. As said functional group, a (meth) acryloyl group, a hydroxymethyl group, an alkoxy methyl group, an epoxy group, a vinyl ether group, etc. are mentioned.

(Content of each component)

The said resist material is a radiation sensitive resin composition containing the said component. When manufacturing a resist material, what is necessary is just to set the compounding ratio of each component suitably in the use, conditions of use, etc. of a resist material.

(1) As a minimum of content of (B) precursor as a radiation sensitive sensitizer for 100 mass parts of components, 0.1 mass part is preferable, 1 mass part is more preferable, 3 mass parts is more preferable, 5 mass parts is especially preferable. As an upper limit of the said content, 50 mass parts is preferable, 30 mass parts is more preferable, 20 mass parts is more preferable, 15 mass parts is especially preferable. If content of the (B) precursor is more than the said minimum, sufficient sensitivity will be easy to be acquired, and if it is below the said upper limit, a rectangular resist pattern will be easy to be obtained.

(1) As a minimum of content of (c) radiation sensitive acid generator with respect to 100 mass parts of components, 1 mass part is preferable, 5 mass parts is more preferable, 10 mass parts is more preferable, 20 mass parts is especially preferable. . As an upper limit of the said content, 50 mass parts is preferable and 40 mass parts is more preferable. (c) Sufficient sensitivity is easy to be obtained that content of a radiation sensitive acid generator is more than the said minimum, and a rectangular resist pattern is easy to be obtained that it is below the said upper limit.

(1) As a minimum of content of the [D] acid diffusion control agent with respect to 100 mass parts of components, 0.1 mass part is preferable, 0.5 mass part is more preferable, 1 mass part is more preferable. As an upper limit of the said content, 20 mass parts is preferable, 10 mass parts is more preferable, 5 mass parts is more preferable. If the content of the acid diffusion control agent (D) is greater than or equal to the above lower limit, the shape of the resist pattern tends to be more favorable, while if less than the upper limit, sufficient sensitivity is likely to be obtained.

(1) As a minimum of content of [E] solvent with respect to 100 mass parts of components, 200 mass parts is preferable and 300 mass parts is more preferable. As an upper limit of the said content, 10,000 mass parts is preferable and 7,000 mass parts is more preferable. If content of the solvent (E) is more than the said minimum, it will become difficult to fall the characteristic of a resist material, and it becomes easy to form a resist film by using below the said upper limit.

The resist material of this embodiment can be manufactured by mixing the said (1) component, (2) component, the [D] acid diffusion control body, the [E] solvent, etc. by a well-known method.

<Resist Pattern Forming Method>

The resist material is suitably used for a two-stage lithography process. That is, the lithography process (resist pattern formation method) which concerns on this embodiment is 250 nm in the process of apply | coating the said resist material to a board | substrate (henceforth a "coating process"), and a part of the resist film formed by the said coating process. A step of irradiating radiation (first radiation) having the following wavelength (hereinafter also referred to as a "partial irradiation step") and a radiation having a wavelength exceeding 250 nm on the entire surface of the resist film after the partial irradiation step (second step) Radiation)) (hereinafter referred to also as "whole surface irradiation process"), a process of heating the resist film after said whole surface irradiation process (hereinafter also referred to as a "heating process"), and a resist film after said heating process The process (henceforth a "development process") is provided.

[Painting process]

In this step, the resist material is coated onto the substrate. As a result, a resist film is formed on the substrate.

The substrate may be composed of a semiconductor wafer such as a silicon substrate, a silicon dioxide substrate, a glass substrate, an ITO substrate, or the like, and an insulating film layer may be formed on the semiconductor wafer.

As a coating method of a resist material, the method of coating a resist material by spin coating etc. is mentioned, for example. When coating the resist material, the solvent in the resist material may be volatilized by heating (prebaking) after coating. The formation conditions of a resist film are suitably selected according to the property of a resist material, the thickness of the resist film obtained, etc. As a minimum of the average thickness of a resist film, 1 nm is preferable, 10 nm is more preferable, and 30 nm is further more preferable. As an upper limit of the said average thickness, 5,000 nm is preferable, 1,000 nm is more preferable, 200 nm is still more preferable.

Prior to forming a resist film on the substrate, an underlayer film (antireflection film, film for improving resist adhesion, film for improving resist shape, etc.) may be formed on the substrate. By forming an anti-reflection film, generation of standing waves due to reflection of radiation on a substrate or the like in some irradiation steps can be suppressed. By forming a film for improving the resist adhesion, the adhesion between the substrate and the resist film can be improved. By forming a film for improving the resist shape, the resist shape after development can be further improved. That is, the drag end shape or the concave shape of the resist can be reduced. On the other hand, in order to prevent the resist shape deterioration by radiation standing wave generation of whole surface irradiation, it is preferable to design so that the thickness of a lower layer film may also suppress reflection of the radiation of whole surface irradiation. It is preferable that an underlayer film is a film which does not absorb the radiation of whole surface irradiation. For example, when the underlayer film absorbs the radiation of the entire surface irradiation, a radiation sensitization reaction occurs in the resist film due to energy transfer or electron transfer from the underlayer film, which may cause acid to occur in some non-irradiating portions. Therefore, the buffer layer which does not propagate a radiation sensitization reaction may be arrange | positioned between a resist film and an underlayer film, and the increase and decrease from the underlayer film which absorbed the radiation may be prevented.

A protective film may be further formed on the resist film. By forming a protective film, deactivation of the radiation sensitive sensitizer, the acid, and these reaction intermediates produced in some irradiation steps can be suppressed, and process stability can be improved. The said protective film may be an absorption film which absorbs at least one part of the wavelength of the radiation which (a) or (c) component directly absorbs in order to prevent the acid generation reaction in the non-irradiation part in a whole surface irradiation process. By using the absorbing film, the out-of-band light (OOB light), which is radiation in the ultraviolet region generated during EUV exposure, is prevented from entering the resist film, thereby preventing decomposition of the radiation-sensitive acid generator in the non-irradiating part. You may. In addition, when the said absorption film is formed directly on a resist film, since the acid generation in the resist film by the radiation sensitization reaction in a non-irradiation part is suppressed, it is made from the protective film at the wavelength of the 2nd radiation in a whole surface irradiation process. It is recommended not to cause radiation sensitization reaction. In addition, a buffer layer may be disposed between the resist film and the protective film so that the radiation-sensitive sensitizer in the resist film does not increase or decrease due to energy transfer or electron transfer from the protective film, or the like. After the partial irradiation step, the absorbing film is formed on the resist film before the whole surface irradiation step to generate the radiation-sensitive acid remaining in the resist film after the partial irradiation step by irradiation of the second radiation in the whole surface irradiation step. Zero direct acid generation can be further suppressed.

[Some survey process]

In this step, part of the resist film formed by the coating step is irradiated with first radiation having a wavelength of 250 nm or less.

In some irradiation processes, a predetermined pattern light shielding mask is disposed on the resist film formed by the coating process. After that, the first radiation is irradiated (pattern exposure) to the resist film through the mask from an exposure apparatus (radiation irradiation module) having a projection lens, an electro-optic mirror, or a reflection mirror.

As an upper limit of the wavelength of the 1st radiation used for partial irradiation, 230 nm is preferable and 200 nm is more preferable. On the other hand, as a minimum of the wavelength of a 1st radiation, 150 nm is preferable and 190 nm is more preferable.

Examples of the first radiation include gamma rays, X-rays, alpha rays, medium particle beams, quantum rays, beta rays, ion beams, electron beams, extreme ultraviolet rays, and the like. Among these, electron beams, extreme ultraviolet rays and ion beams are preferable, and electron beams and extreme ultraviolet rays are more preferable.

[Full Surface Irradiation Process]

In this step, second radiation having a wavelength exceeding 250 nm is irradiated to the entire surface of the resist film after the partial irradiation step.

In the whole surface irradiation step, in the case of a high-sensitivity module (exposure device or irradiation module) having a projection lens (or a light source) on the entire surface of the resist film after the partial irradiation step (the whole surface in which some irradiation portions and non-some irradiation portions are combined) Second radiation is irradiated (collective exposure). As this whole surface irradiation, you may irradiate the whole wafer surface at once, may combine local irradiation, or may overlap and irradiate. A general light source can be used as the light source for the entire surface irradiation, and by passing through a bandpass filter or a cutoff filter, in addition to ultraviolet rays from mercury lamps and xenon lamps controlled at desired wavelengths, Ultraviolet light of a narrow band may be sufficient. In the whole surface irradiation, only the (A) sensitizer generated in a part of the irradiation part in the resist material film absorbs radiation. For this reason, in whole surface irradiation, absorption of a radiation selectively occurs in some irradiation parts. Therefore, acid can be continuously generated only in some irradiation part during whole surface irradiation, and it becomes possible to greatly improve a sensitivity. On the other hand, since acid does not generate | occur | produce in some non-irradiation parts, sensitivity can be improved, maintaining chemical contrast in a resist film.

As a minimum of the wavelength of a 2nd radiation, 280 nm is more preferable, and 320 nm is further more preferable. When generating the radiation sensitive sensitizer which can absorb radiation of a longer wavelength, the wavelength of 2nd radiation may be 350 nm or more. However, when the wavelength of the second radiation is too long, the efficiency of the radiation sensitization reaction is inferior, so that the base component, the radiation sensitive acid generator, and the radiation sensitive sensitizer generator avoid the wavelength of the radiation that can be absorbed. It is preferable to use radiation of a wavelength as short as possible that the radiosensitizer can absorb. From this viewpoint, 450 nm is preferable and 400 nm is more preferable as a minimum of the wavelength of 2nd radiation.

[Heating process]

In the heating step, the resist film after the whole surface irradiation step is also heated (hereinafter also referred to as "post flood exposure bake (PFEB)" or "post exposure bake (PEB)"). As heating conditions, it can be 50 degreeC or more and 200 degrees C or less, 10 second or more and 300 second or less, for example in inert gas atmosphere, such as nitrogen and argon, in air | atmosphere. By setting the heating conditions in the above range, there is a tendency that the diffusion of the acid can be controlled and the processing speed of the semiconductor wafer can be ensured. In the heating step, the polarity change reaction such as the deprotection reaction of the base component, the crosslinking reaction, and the like occur by the acid generated in the partial irradiation step and the whole surface irradiation step. In addition, although the sidewalls of the resist may be bent under the influence of the standing wave of the radiation in the resist film, the bend can be reduced by the diffusion of the reactant in the heating step.

[Developing process]

In the developing step, the resist film after the heating step is developed. By the reaction in the resist film in the said heating process, it develops using what changes the solubility to a developing solution selectively in some irradiation part, and a resist pattern is formed. The developer can be divided into a positive developer and a negative developer.

As the positive developer, an alkaline developer is preferable. The alkaline developer selectively dissolves the high polarity portion of the resist material film after irradiation. As an alkaline developing solution, at least 1 sort (s) of alkaline compounds, such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines (ethanolamine, etc.), tetraalkylammonium hydroxide (TAAH), is melt | dissolved, for example. Alkaline aqueous solution etc. are mentioned. As the alkaline developer, an aqueous solution of TAAH is preferable. As TAAH, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc. are mentioned, for example.

2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) is used widely for positive developer.

In alkali development, a pattern is formed using the phenomenon in which the carboxylic acid and hydroxyl group produced in a resist film after ionizing irradiate and elute in an alkaline developing solution. After image development, the water washing process called a rinse is performed in order to remove the developer which remains on the board | substrate.

As a negative developer, an organic developer is preferable. The organic developer selectively dissolves a portion of low polarity of the resist film after irradiation. Organic developer is used to improve resolution and process window in exclusion patterns such as holes and trenches (grooves). In this case, due to the difference in affinity between the solvent in the resist film and the organic developer, the dissolution contrast of some of the irradiated portions and non-illuminated portions is obtained. The part with high polarity has low solubility with respect to organic developing solution, and remains as a resist pattern. As the organic developer, for example, 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexa Paddy, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate Methyl acid, methyl pentene, methyl crotonate, ethyl crotonate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, iso lactate Wheat, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenyl acetate, benzyl formate, phenyl ethyl formate, 3-phenylpropionate Propionate, benzyl, phenyl ethyl, and the like can be mentioned acetic acid 2-phenylethyl.

(Formation of substrate pattern)

The substrate pattern is formed by etching or ion implanting the underlying substrate using the resist pattern formed by the resist pattern forming method as a mask. The etching may be a dry etching under an atmosphere such as plasma excitation or a wet etching immersed in a chemical liquid. After the pattern is formed on the substrate by etching, the resist pattern is removed.

Example

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The measuring method of the physical property value in a present Example is shown below.

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

Mw and Mn of the polymer were 1.0 mL / min flow rate, elution solvent tetrahydrofuran, sample concentration 1.0 mass using a GPC column (two "G2000HXL", one "G3000HXL", one "G4000HXL" of Tosoh Corporation). %, The sample injection amount 100 microliters, and the analysis conditions of column temperature 40 degreeC, it measured by the gel permeation chromatography (GPC) which makes monodisperse polystyrene the standard using a differential refractometer as a detector.

¹³ C-NMR Analysis

¹³ C-NMR analysis for obtaining the content ratio of the structural unit of the polymer was carried out using tetramethylsilane (TMS) using CDCl ₃ as a measurement solvent using a nuclear magnetic resonance apparatus (“JNM-ECX400” manufactured by Nippon Denshi Corporation). ) Was used as an internal standard.

<Synthesis of polymer [P]>

[P] The monomer used for the synthesis | combination of a polymer is shown below.

In addition, the said compound (M-1) is a structural unit (I), the compound (M-2) is a structural unit (II), (M-3) a structural unit (III) by deacetylation, a compound (M-4) provides structural unit (IV), respectively. In addition, unless otherwise indicated in the following polymer synthesis examples, a mass part means the value at the time of making the total mass of the used monomer 100 mass parts, and mole% is a case where the total mole number of the used monomer is 100 mol%. It means the value.

Synthesis Example 1 (Synthesis of Polymer (P1))

In the reaction vessel, the compound (M-1) and the compound (M-2) as monomers were dissolved in 300 parts by mass of 2-butanone such that the molar ratio was 50/50. 3 mass parts of AIBN as a radical polymerization initiator were added here, and nitrogen purge was carried out for 30 minutes. The polymerization reaction was carried out for 6 hours while stirring the inside of the reaction vessel at 78 ° C. After completion | finish of a polymerization reaction, the polymerization solution was cooled by water and cooled to 30 degrees C or less. The cooled polymerization solution was poured into 2,000 parts by mass of methanol, and the precipitated white powder was separated by filtration. The white powder separated by filtration was washed twice with methanol, then filtered and dried at 50 ° C. for 17 hours to obtain a white powdery polymer (P1) in good yield. Mw of the polymer (P1) was 7,000, and Mw / Mn was 2.10. ^As a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (M-1) and (M-2) was 52 mol% and 48 mol%, respectively.

Synthesis Example 2 (Synthesis of Polymer (P2))

In the reaction vessel, the compound (M-1) and the compound (M-3) as monomers were dissolved in 150 parts by mass of propylene glycol monomethyl ether so that the molar ratio was 44/56. 3 mass parts of AIBN as a radical polymerization initiator, and 1 mass part of t-dodecyl mercaptans as a chain transfer agent were added here, and the monomer solution was produced. The monomer solution was maintained under a nitrogen atmosphere at a reaction temperature of 70 ° C., and polymerization was carried out for 16 hours. After completion | finish of a polymerization reaction, the polymerization solution was dripped in 1,000 mass parts of n-hexane, and the polymer was coagulated-purified. 150 mass parts of propylene glycol monomethyl ethers were added to the said polymer. Furthermore, 150 mass parts of methanol, 37 mass parts of triethylamines, and 7 mass parts of water were added, and the hydrolysis reaction was performed for 8 hours, refluxing to boiling point. After the completion of reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained polymer was dissolved in 150 parts by mass of acetone. This was dripped in 2,000 mass parts of water, it solidified, and the produced white powder was separated by filtration. It dried at 50 degreeC for 17 hours, and obtained the white powdery polymer (P2) by favorable yield. Mw of the polymer (P2) was 6,000, and Mw / Mn was 1.90. ^As a result of ¹³ C-NMR analysis, each content rate of the structural unit derived from (M-1) and the structural unit derived from p-hydroxy styrene obtained by deacetylation of (M-3) is 50 mol, respectively. % And 50 mole%.

Synthesis Example 3 (Synthesis of Polymer (P3))

In the reaction vessel, the compound (M-1), the compound (M-3) and the compound (M-4) as monomers were dissolved in 200 parts by mass of propylene glycol monomethyl ether so that the molar ratio was 40/40/20. . 4 mass parts of AIBN as a radical polymerization initiator were added here, and the monomer solution was produced. 100 mass parts of propylene glycol monomethyl ethers were put into another reaction container, the reaction temperature was maintained at 80 degreeC, the monomer solution prepared above was dripped over 3 hours, and it superposed | polymerized further for 3 hours. After the completion of the polymerization, the polymerization reaction solution was cooled with water and cooled to 30 ° C or lower. The polymerization solution was added dropwise into 2,000 parts by mass of n-hexane, and the polymer was coagulated and purified. The filtration fractionated solid content was washed twice with 400 parts by weight of hexane, and then filtered filtration and dried at 50 ° C for 17 hours. 100 mass parts of propylene glycol monomethyl ethers were added to the said polymer. 17.5 mass parts of triethylamines and 2.8 mass parts of water were added, it heated at 80 degreeC, and the hydrolysis reaction was performed for 6 hours. After completion | finish of reaction, after completion | finish of hydrolysis, the reaction liquid was cooled by water and cooled to 30 degrees C or less. The obtained polymer was poured into 2,000 parts by mass of hexane, and the precipitated solid content was separated by filtration. The solid fractions separated by filtration were washed twice with 40 parts by weight of hexane, and further filtered and dried at 50 ° C. for 17 hours to obtain polymer (P3) in good yield. Mw of the polymer (P3) was 7,500, and Mw / Mn was 1.52. ¹³ C-NMR analysis showed that the structural units derived from (M-1), the p-hydroxystyrene structural units obtained by deacetylation of (M-3), and the structural units derived from (M-4) Each content rate was 40 mol%, 40 mol%, and 20 mol%, respectively.

In Table 1, it shows about Mw, Mw / Mn of the obtained polymer (P1)-(P3), and the content rate of each structural unit.

The content rate of the structural unit of (M-3) in the said Table 1 shows the content rate as a structural unit derived from p-hydroxy styrene obtained by deacetylating the structural unit derived from (M-3).

Synthesis of [B] Precursor

Synthesis Example 4

50 mmol of 3,4-dihydroxybenzophenone, 50 mmol of 2,2-dimethoxypropane, 0.05 g of p-toluenesulfonic acid monohydrate and 400 g of toluene were added to the reaction vessel. After carrying out dehydration heating reflux by Dean-Stark for 3 hours, the reaction solution was cooled. After cooling overnight, 3, 4- dihydroxy benzophenone of the raw material which precipitated was separated by filtration, and 0.2 g of sodium methoxymethanol solution (28 mass%) was added to the filtrate and neutralized. The neutralization liquid was concentrated under reduced pressure, and then purified by alumina column chromatography to obtain a compound represented by the following formula (B1).

Synthesis Example 5

79.7 mmol of 3,4-dihydroxybenzophenone, 2,000 mmol of trimethyl ortho formate, 0.1 g of p-toluenesulfonic acid monohydrate, and 40 g of toluene were added to the reaction vessel. After performing dehydration heating reflux by Dean-Stark for 12 hours, the reaction solution was cooled. After cooling overnight, 0.2 g of sodium methoxide methanol solution (28% by mass) was added to the filtrate and neutralized. The neutralization liquid was concentrated under reduced pressure, and then purified by alumina column chromatography to obtain a compound represented by the following formula (B2).

Synthesis Example 6

231 mmol of 4,4'-dihydroxybenzophenone, 2,160 mmol of ethylene glycol, 913 mmol of orthoformate trimethyl, and 0.5 g of p-toluenesulfonic acid monohydrate were added to the reaction vessel in which the Dean-Stark apparatus was set. After heating and stirring at 80 ° C for 2 hours, the heating temperature was gradually raised to 120 ° C, and heating was continued while removing the effluent until the outflow of methanol, methyl formate, and trimethyl ortho formate was completed. The reaction solution was cooled to room temperature, diluted with ethyl acetate, the organic phase was washed with 5% by weight of an aqueous sodium bicarbonate solution, and the organic phase was concentrated under reduced pressure. 80 mL of methylene chloride was added to the obtained concentrate for crystallization, the obtained crystals were separated by filtration, and the crystals were washed with methylene chloride cooled to 5 ° C to obtain a compound represented by the following formula (B3).

<Screening evaluation of sensitizers>

[Production of resist material for sensitizer screening]

A resist material for screening a sensitizer was produced. It shows below about components other than the [P] polymer used for manufacture.

((A) sensitizer)

A1 and A2 and CA1 to CA4: compounds represented by the following formulas (A1) and (A2) and (CA1) to (CA4)

([C] radiation-sensitive acid generator)

C1: the compound represented by following formula (C1)

([D] acid diffusion control agent)

D1: the compound represented by following formula (D1)

([E] solvent)

E1: Propylene Glycol Monomethyl Ether

E2: ethyl lactate

[Production Example 1]

[P] 100 mass parts of (P3) as a polymer, (A) 10 mass parts of (A1) as a sensitizer, [C] 20 mass parts of (C1) as a radiation sensitive acid generator, and [D] as an acid diffusion control agent 0.3 mass part (D1) and 4,300 mass parts of (E1) as a solvent [E], and 1,900 mass parts of (E2) were mixed. The obtained liquid mixture was filtered with the membrane filter of 0.20 micrometer of pore diameters, and the resist material for sensitizer screening (S-1) was manufactured.

[Production Examples 2 to 7]

Resist materials (S-2) and (CS-1) to (CS-5) were produced in the same manner as in Production Example 1, except that the type and amount of the (A) sensitizer shown in Table 2 was changed. "-" In Table 2 shows that the corresponding component is not used.

[Sensitizer Screening Evaluation]

After spin coating the prepared resist material on a silicon wafer in "Clean Track ACT-8" manufactured by Tokyo Electron, PB was performed at 130 ° C for 60 seconds to form a resist film having an average thickness of 50 nm. Subsequently, an i-line stepper ("NSR2205i12D" of Nikon Corporation) was irradiated to this resist film at 1,000 mJ / cm <2> in an area | region of 0.5 cm square to a resist film. After irradiation of i-line, PEB was performed in the said clean track ACT-8 on the conditions of 110 degreeC and 60 second, Then, in the said clean track ACT-8, using 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, It developed by the puddle method at 23 degreeC for 1 minute. After development, a positive resist pattern was formed by washing with water and drying. After this treatment, the film thickness in the i-ray irradiation unit was confirmed, and the remaining film was 0, that is, the resolution was called A (good), and the one that was not resolved was B (bad). The evaluation results are shown in Table 3 below. In this test, as for A (good), the sensitizer absorbs i-rays and is excited, and energy or electron transfer takes place efficiently from the exciton to the radiation-sensitive acid generator, and the acid is released from the radiation-sensitive acid generator. It is assumed that the deprotection reaction of the polymer proceeds.

<Production of Chemically Amplified Resist Material>

The chemically amplified resist material was manufactured using the [B] precursor which gives (A) sensitizer which showed the effect in the screening evaluation of the said sensitizer. In addition, benzophenone dimethyl ketal (Tosei Kasei Kogyo Co., Ltd.) (previous Table 3 was used as "CB1") which is a precursor of the sensitizer (CA4) used as said resist material (CS-4) was used for the resist material of a comparative example. did.

Example 1

[P] 100 parts by mass of (P3) as the polymer, 10 parts by mass of (B1) as the [B] precursor, 20 parts by mass of (C1) as the [C] radiation-sensitive acid generator, and (D) as the acid diffusion control agent ( D1) 2.0 mass parts, 4,300 mass parts of (E1) as a solvent [E], and 1,900 mass parts of (E2) were mixed. The obtained liquid mixture was filtered with the membrane filter of 0.20 micrometer of pore diameters, and chemically amplified resist material (R-1) was produced.

[Examples 2 and 3 and Comparative Examples 1 and 2]

Chemically amplified resist materials (R-2) and (R-3) and (CR-1) and (CR) were prepared in the same manner as in Example 1, except that the type and amount of the [B] precursor shown in Table 4 below was changed. -2) was prepared. "-" In Table 4 shows that the corresponding component is not used.

<Evaluation>

In Tokyo Electron Corporation's "Clean Track ACT-8", after spin coating the above-described chemically amplified resist material on a silicon wafer, PB was performed at 130 ° C for 60 seconds to form a resist film having an average thickness of 50 nm. did. The electron beam was irradiated to the resist film using the simple type electron beam drawing apparatus ("HL800D" of Hitachi Seisakusho Co., Ltd., output 50 KeV, current density 5.0 A / cm <2>), and patterning was performed. As a patterning method, the operation which irradiates predetermined | prescribed exposure amount to the area | region of 0.5 cm square was performed 50 points in total for every 1 micrometer / cm <2> from 1 microC / cm <2> -50 microC / cm <2>. After irradiation of an electron beam, each operation of the following (1) and (2) was performed continuously, and evaluation was performed.

(Operation (1): no full-surface irradiation)

After irradiation of an electron beam, PEB was performed in the said clean track ACT-8 on the conditions of 110 degreeC and 60 second, Then, in the said clean track ACT-8, using a 2.38 mass% TMAH aqueous solution for 1 minute at 23 degreeC, It developed by the puddle method. After development, a positive resist pattern was formed by washing with water and drying.

(Operation (2): with full-surface survey)

After irradiation of the electron beam, the whole surface of the resist film was exposed at 2,000mJ / cm <2> using LED (wavelength 365nm) of Hamamatsu Photonics. Next, PEB was performed in the said clean track ACT-8 on the conditions of 110 degreeC and 60 second. Then, it developed, washed with water, and dried similarly to the said operation (1), and formed the positive resist pattern.

With respect to the formed positive resist pattern, the electron beam exposure amount at which the film thickness in the case of performing in the operation (1) is 0 is called E1 (μC / cm 2), and the film thickness in the case of performing in the operation (2) is 0. When the electron beam exposure dose is E2 (μC / cm2), A (increase or decrease effect) is obtained when (E2 / E1) <0.8, and B (increase or decrease effect is obtained when (E2 / E1) ≥ 0.8 is obtained. No increase or decrease effect). The evaluation results are shown in Table 5 below.

From the results in Table 5, the precursor was generated by the generation of acid from the radiation-sensitive acid generator by electron beam exposure only when using a precursor of a sensitizer recognized as having a sensitizing effect with respect to 365 nm irradiation by screening evaluation of i-ray exposure. Is converted into a sensitizer, and the decomposition of the radiation-sensitive acid generator is further promoted by the sensitization effect by full-surface irradiation of 365 nm light, which results in deprotection and resolution of the polymer at a small electron beam exposure amount. I guess it could.

According to the present invention, in a pattern forming technique using radiation having a wavelength of 250 nm or less, such as EUV light, electron beam, ion beam, KrF excimer laser, ArF excimer laser, both high sensitivity and excellent lithography characteristics can be achieved at a high level. A chemically amplified resist material is provided. Moreover, according to this invention, the pattern formation method using the said resist material is provided.

Claims (9)

Irradiating a part of the resist film formed using the photosensitive resin composition with the first radiation having a wavelength of 250 nm or less;
Irradiating a second radiation having a wavelength exceeding 250 nm to the entire surface of the resist film after the partial irradiation step;
Heating the resist film after the whole surface irradiation step;
Process of developing the resist film after the said heating process with a developing solution
In the lithography process provided with, as a chemically amplified resist material used as said photosensitive resin composition,
(1) a base component soluble or insoluble in the developer by the action of an acid,
(2) Components that generate radiation-sensitive sensitizers and acids by irradiation
Including,
The said (2) component contains the following (a) and (b) component, the following (b) and (c) component, or all of the following (a)-(c) components,
The chemically amplified resist material in which the component (b) is decomposed by the action of an acid and generates a compound represented by the following formula (A).
(a) In the non-irradiation part which generate | occur | produces an acid and the radiation sensitive sensitizer which absorbs the said 2nd radiation by irradiation of the said 1st radiation, and the 1st radiation is not irradiated in the said some irradiation process, 2nd radiation A radiation-sensitive acid-sensitizer generator in which the acid and the radiation-sensitive sensitizer are substantially not generated by irradiation of
(b) In the non-irradiation part which generate | occur | produces the radiation sensitive sensitizer which absorbs a 2nd radiation by the said 1st irradiation, and in which the 1st radiation is not irradiated in the said partial irradiation process, it irradiates for 2nd radiation A radiation sensitive sensitizer generator in which said radiation sensitive sensitizer is not substantially generated by
(c) Radiation radiation which does not generate | occur | produce substantially the said acid by irradiation of a 2nd radiation in the non-irradiation part which generate | occur | produces an acid by irradiation of the said 1st radiation and in which the 1st radiation is not irradiated in the said partial irradiation process. Acid generator

(In formula (A), R ^a to R ^d are each independently a hydrogen atom, an amino group, a sulfanyl group, a halogen atom or a C 1-20 monovalent organic group, and R ¹ to R ⁶ are each independently hydrogen An atom, a hydroxy group, an amino group, a sulfanyl group, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, or two or more of R ^a to R ^d and R ¹ to R ⁶ join together to form a carbon chain to which they are bonded Is part of a ring structure of reduced water 4 to 20. However, at least one of R ¹ to R ⁶ is a hydroxy group.) (1) a base component that is soluble or insoluble in a developer by the action of an acid,
(2) Components that generate radiation-sensitive sensitizers and acids by irradiation
Including,
The said (2) component contains the following (a) and (b) component, the following (b) and (c) component, or all of the following (a)-(c) components,
The chemically amplified resist material in which the component (b) is decomposed by the action of an acid and generates a compound represented by the following formula (A).
(a) Irradiation of the first radiation having a wavelength of 250 nm or less generates a radiation-sensitive sensitizer which absorbs an acid and a second radiation having a wavelength exceeding 250 nm, and does not irradiate the first radiation. And a radiation-sensitive acid-sensitizer generator that does not substantially generate the acid and the radiation-sensitive sensitizer when only the second radiation is irradiated.
(b) The radiation-sensitive sensitizer is generated when the radiation-sensitive sensitizer that absorbs the second radiation is generated by the irradiation of the first radiation, and only the second radiation is irradiated without irradiating the first radiation. Radiation-sensitive sensitizers that do not occur substantially
(c) A radiation-sensitive acid generator that does not substantially generate the acid when the acid is generated by irradiation of the first radiation and only the second radiation is irradiated without irradiating the first radiation.

(In formula (A), R ^a to R ^d are each independently a hydrogen atom, an amino group, a sulfanyl group, a halogen atom or a C 1-20 monovalent organic group, and R ¹ to R ⁶ are each independently hydrogen An atom, a hydroxy group, an amino group, a sulfanyl group, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, or two or more of R ^a to R ^d and R ¹ to R ⁶ join together to form a carbon chain to which they are bonded Is part of a ring structure of reduced water 4 to 20. However, at least one of R ¹ to R ⁶ is a hydroxy group.) The chemically amplified resist material according to claim 1 or 2, wherein at least two of R ¹ to R ⁶ in the formula (A) are hydroxyl groups. The chemically amplified resist material according to any one of claims 1 to 3, wherein R ² in the formula (A) is a hydroxy group. The chemically amplified resist material according to claim 4, wherein the precursor is represented by the following formulas (B-1) to (B-4).

(In formula (B-1)-(B-4), R ^<a> -R <^d> is respectively independently a hydrogen atom, an amino group, a sulfanyl group, a halogen atom, or a C1-C20 monovalent organic group, and R <^1> - R ⁶ is each independently a hydrogen atom, a hydroxyl group, an amino group, a sulfanyl group, a halogen atom or a monovalent organic group having 1 to 20 carbon atoms, or two or more of R ^a to R ^d and R ¹ to R ⁶ are combined with each other Are part of a ring structure of reduced water of 4 to 20, together with the carbon chain to which they are bonded, R ^A and R ^B are each independently a monovalent organic group having 1 to 20 carbon atoms, or their groups are joined to each other Is part of a ring structure of reduced water 4 to 20 composed together with OCO, R ^C and R ^D are each independently a monovalent organic group having 1 to 20 carbon atoms, or their groups are joined together to form a carbon atom to which they are bonded Ring composed Be a part of the ring structure of 3 to 20.) The chemically amplified resist material according to any one of claims 1 to 5, wherein the component (1) is a polymer whose solubility in a developing solution changes due to the action of an acid. The chemically amplified resist material according to any one of claims 1 to 6, wherein (c) a component includes (c) a radiation sensitive acid generator. The chemically amplified resist material according to any one of claims 1 to 6, wherein the component (2) contains a polymer having an acid-generating group. Coating the chemically amplified resist material according to any one of claims 1 to 8 onto a substrate;
Irradiating a part of the resist film formed by the coating process with radiation having a wavelength of 250 nm or less;
Irradiating radiation having a wavelength exceeding 250 nm to the entire surface of the resist film after the partial irradiation step;
Heating the resist film after the whole surface irradiation step;
Process of developing the resist film after the said heating process
Resist pattern forming method comprising a.