JP2017203858A - Radiation-sensitive resin composition for ion implantation and method for manufacturing semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition for ion implantation excellent in DOF performance in ISO-TAP pattern formation.SOLUTION: A radiation-sensitive resin composition for ion implantation contains a polymer component having a first structural unit containing a first acid dissociable group having a bridge bond and a second structural unit containing a second acid dissociable group other than the first acid dissociable group in the same or different polymer, a radiation-sensitive acid generator and a solvent, where a content ratio of the first structural unit with respect to the total of the first structural unit and the second structural unit in the polymer component is 5 mol% or more and 80 mol% or less, and the total content of the component other than the solvent is 2 mass% or more and 6 mass% or less. The polymer component preferably contains a polymer having the first structural unit and the second structural unit or is a mixture having the polymer having the first structural unit and the polymer having the second structural unit.SELECTED DRAWING: None

Description

  The present invention relates to a radiation-sensitive resin composition for ion implantation and a method for producing a semiconductor element.

  A chemically amplified photoresist composition used for microfabrication by lithography is used to irradiate exposed portions with exposure light such as far ultraviolet rays such as ArF excimer laser light, electromagnetic waves such as X-rays, and charged particle beams such as electron beams. Is generated. A resist pattern can be formed on the substrate by causing a difference in the dissolution rate of the exposed portion and the unexposed portion in the developer by a chemical reaction using this acid as a catalyst (Japanese Patent Laid-Open No. 59-45439). Gazette, JP-A-60-52845 and JP-A-2-25850).

  The resist pattern formed in this way is used as a mask for ion implantation in which ions are implanted into a substrate, and is used for manufacturing a semiconductor element including an ion-implanted inorganic substrate (Japanese Patent Laid-Open No. 2004-2004). No. 233656 and JP-A-2005-316136). On the other hand, due to the complexity of the structure of integrated circuit elements in recent years, there is an increasing need to form various patterns such as line and space (LS), contact holes (CH), and cylindrical convex structure ISO-TAP. In forming these patterns, it is particularly required to have excellent depth of focus. However, with the conventional radiation sensitive resin composition for ion implantation, it is difficult to satisfactorily form an ISO-TAP-shaped resist pattern. In particular, the radiation sensitive resin composition for ion implantation having excellent DOF performance is unknown.

JP 59-45439 A JP-A-60-52845 JP-A-2-25850 JP 2004-233656 A JP 2005-316136 A

  The present invention has been made based on the above circumstances, and an object thereof is to provide a radiation-sensitive resin composition for ion implantation excellent in DOF performance in ISO-TAP pattern formation and a method for manufacturing a semiconductor element. There is.

  The invention made in order to solve the above-mentioned problem is a first structure comprising a first acid-dissociable group having a bridge-like bond (hereinafter also referred to as acid-dissociable group (I)) in the same or different polymers. A unit containing a unit (hereinafter also referred to as “structural unit (I)”) and a second acid dissociable group (hereinafter also referred to as “acid dissociable group (II)”) other than the acid dissociable group (I). A polymer component (hereinafter also referred to as “[A] polymer component”) having two structural units (hereinafter also referred to as “structural unit (II)”), a radiation-sensitive acid generator (hereinafter referred to as “[B]”). An acid generator ”) and a solvent (hereinafter also referred to as“ [C] solvent ”), and a structure relative to the sum of the structural unit (I) and the structural unit (II) in the polymer component [A]. The content of the unit (I) is 5 mol% or more and 80 mol% or less, and the total content of components other than the above [C] solvent There is an ion implantation for radiation-sensitive resin composition is 6% less than 2 wt%.

  Another invention made in order to solve the above-described problems includes a step of forming a film on the surface of an inorganic substrate, a step of exposing the film, a step of developing the exposed film, and a mask of the film after development. And a step of ion-implanting the inorganic substrate, wherein the film is formed from the radiation-sensitive resin composition for ion implantation.

  Here, the “acid-dissociable group” refers to a group that replaces a hydrogen atom of a carboxy group, a hydroxy group, or the like and dissociates by the action of an acid.

  According to the radiation sensitive resin composition for ion implantation of the present invention and the method for manufacturing a semiconductor device, an ISO-TAP pattern can be formed by exhibiting excellent DOF performance, and such an excellent pattern is masked. By doing so, a semiconductor element including an inorganic substrate in which ions are implanted in a desired region can be manufactured. Accordingly, these can be suitably used for the manufacture of semiconductor products and the like, and the performance, reliability, yield, etc. of the products can be improved.

<Radiation-sensitive resin composition for ion implantation>
The radiation-sensitive resin composition for ion implantation (hereinafter also simply referred to as “the radiation-sensitive resin composition”) is used to form a mask for ion implantation, that is, ion implantation into an inorganic substrate or the like. Is preferably used.

  The radiation sensitive resin composition contains a [A] polymer component, a [B] acid generator, and a [C] solvent. The radiation-sensitive resin composition may contain a [D] acid diffusion controller as a suitable component, and may contain other optional components as long as the effects of the present invention are not impaired.

  In the radiation-sensitive resin composition, the [A] polymer component has the structural unit (I) and the structural unit (II), and the structural unit (I) and the structural unit (II) in the [A] polymer component. The content ratio of the structural unit (I) with respect to the total of 5 mol% to 80 mol%, and the total content of components other than the above [C] solvent is 2 mass% to 6 mass%. -Excellent DOF performance in TAP formation. The reason why the radiation-sensitive resin composition has the above-described configuration and thus exhibits the above-mentioned effects is not necessarily clear, but can be inferred as follows, for example. That is, by setting the total content of components other than the [C] solvent of the radiation-sensitive resin composition (hereinafter also referred to as “solid content concentration”) within the specific range, the application of the radiation-sensitive resin composition is performed. Workability can be improved and the formability of the resist film can be improved. In addition, by setting the ratio of those having acid-dissociable groups in the polymer component [A] having a bridge-like bond within the specific range, the solubility of the polymer component [A] during development is more appropriate. Can be adjusted. As a result, it is considered that the radiation-sensitive resin composition can improve the DOF performance when a pattern having a specific shape such as ISO-TAP is formed. Hereinafter, each component will be described.

<[A] Polymer component>
[A] The polymer component has the structural unit (I) and the structural unit (II) in the same or different polymers, and the structural unit (I) with respect to the sum of the structural unit (I) and the structural unit (II). ) Is 5 mol% or more and 80 mol% or less. That is, the [A] polymer component comprises a polymer having the structural unit (I) and / or the structural unit (II), and the structural unit (I) and the structural unit (II) in the entire [A] polymer component. The content ratio of the structural unit (I) with respect to the total of is in the above range.

  [A] As the polymer component, for example, a base polymer in the radiation-sensitive resin composition (hereinafter also referred to as “[A1] polymer”), the mass content of fluorine atoms than the [A1] polymer. Polymer having a large diameter (hereinafter also referred to as “[A2] polymer”) and the like. “Base polymer” refers to a polymer that is a main component of a resist film formed by the radiation-sensitive resin composition, and preferably 50% by mass or more based on the total polymer constituting the resist film. Is a polymer. The radiation-sensitive resin composition usually contains a [A1] polymer as the [A] polymer component. Since the [A2] polymer has a higher mass content of fluorine atoms than the [A1] polymer, its distribution is unevenly distributed in the resist film surface layer when the resist film is formed due to its water and oil repellency characteristics. Tend. As a result, according to the radiation sensitive resin composition containing the [A2] polymer in addition to the [A1] polymer, the [B] acid generator, the [D] acid diffusion controller, etc. at the time of immersion exposure Elution into the immersion medium can be suppressed. Further, according to the radiation sensitive resin composition containing both the [A1] polymer and the [A2] polymer as the [A] polymer component, due to the water repellency characteristics of the [A2] polymer, The advancing contact angle with the immersion medium can be controlled within the desired range, the generation of bubble defects can be suppressed, and the receding contact angle between the resist film and the immersion medium is increased, allowing high-speed scanning without leaving water droplets. Since exposure is possible, a resist film suitable for the immersion exposure method can be formed.

[A2] The lower limit of the mass content of fluorine atoms in the polymer is preferably 1% by mass, more preferably 2% by mass, further preferably 4% by mass, and particularly preferably 7% by mass. As an upper limit of the said mass content rate, 60 mass% is preferable, 50 mass% is more preferable, 40 mass% is further more preferable, 30 mass% is especially preferable. By making the mass content rate of a fluorine atom into the said range, uneven distribution in the resist film of [A2] polymer can be adjusted more appropriately. The mass content of fluorine atoms in the polymer can be calculated from the structure of the polymer obtained by ¹³ C-NMR spectrum measurement.

  Moreover, as a content aspect of the [A] polymer component in the said radiation sensitive resin composition, the form containing the polymer which has (i) structural unit (I) and structural unit (II), for example, (ii) Structure The form which is a mixture containing the polymer having the unit (I) and the polymer having the structural unit (II), (iii) both of the forms (i) and (ii), and the like. Among these, from the viewpoint of further improving the DOF performance in ISO-TAP formation, the above (ii) and (iii) are preferable, and the above (ii) is more preferable.

  [A] The polymer component includes a structural unit (III) containing a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof in a polymer having the structural unit (I) and / or the structural unit (II), and It is preferable to have a structural unit (IV) containing an alcoholic hydroxyl group and may have other structural units other than the structural units (I) to (IV). [A2] The polymer usually has a structural unit (F) containing a fluorine atom in the polymer having the structural unit (I) and / or the structural unit (II). [A] The polymer component may have one or more of these structural units. Hereinafter, each structural unit will be described.

[Structural unit (I)]
The structural unit (I) is a structural unit containing an acid dissociable group (I).

(Acid-dissociable group (I))
The acid dissociable group (I) is an acid dissociable group having a bridge bond. “Bridge-like bond” refers to a bond in a form straddling non-adjacent carbon atoms constituting an alicyclic ring, for example, in a camphor molecule.

  Examples of the bridge-like bond include a substituted or unsubstituted divalent chain hydrocarbon group having 1 or 2 carbon atoms. Examples of the divalent chain hydrocarbon group having 1 carbon atom include a methanediyl group. Examples of the chain hydrocarbon group having 2 carbon atoms include an ethanediyl group and an ethenediyl group. Examples of the substituent of the chain hydrocarbon group include alkyl groups such as methyl group and ethyl group, halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, cyano group, hydroxy group, nitro group and amino group. Is mentioned. Among these, an alkyl group is preferable and a methyl group is more preferable.

  Examples of the ring containing a bridge-like bond include a norbornane ring, an adamantane ring, a tricyclodecane ring, a tetracyclododecane ring, and the like. Of these, an adamantane ring is preferred.

  Examples of the acid dissociable group (I) include an acid dissociable group represented by the following formula (1-1) (hereinafter also referred to as “acid dissociable group (I-1)”), ) Or the like (hereinafter also referred to as “acid-dissociable group (II-1)”).

In the above formula (1-1), ^{R 1} is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ² and R ³ are each independently a trivalent chain hydrocarbon group having 1 to 20 carbon atoms or a trivalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. R ⁴ is a substituted or unsubstituted divalent chain hydrocarbon group having 1 or 2 carbon atoms. * ¹ represents a binding site to a moiety other than the acid dissociable group (I-1) in the structural unit (I).
In the above formula (1-2), ^{R 5} and ^{R 6} are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ⁷ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ⁸ and R ⁹ are each independently a trivalent chain hydrocarbon group having 1 to 20 carbon atoms or a trivalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. R ¹⁰ is a substituted or unsubstituted divalent chain hydrocarbon group having 1 or 2 carbon atoms. R ⁷ and R ⁸ may be combined with each other to form an alicyclic structure having 5 to 20 ring members together with the carbon atom to which R ⁷ is bonded, R ⁸ , R ⁹ and R ¹⁰ . * ² represents a binding site to a moiety other than the acid dissociable group (I-2) in the structural unit (I).

  The acid dissociable group (I-1) and the acid dissociable group (I-2) are usually bonded to an oxyoxygen atom derived from a hydroxy group or a carboxy group in the structural unit (I). As a result, these groups are dissociated by the action of an acid to produce a hydroxy group or a carboxy group.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ¹ , R ⁵ , R ⁶ and R ⁷ include, for example, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and 3 to 3 carbon atoms. 20 monovalent alicyclic hydrocarbon groups, monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, and the like.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, and a butyl group;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group and butynyl group.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monovalent alicyclic saturated hydrocarbon groups such as a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a norbornyl group, and an adamantyl group;
And monovalent alicyclic unsaturated hydrocarbon groups such as a cyclopentenyl group, a cyclohexenyl group, and a norbornenyl group.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as phenyl group, tolyl group, xylyl group, mesityl group, and naphthyl group;
Examples thereof include aralkyl groups such as benzyl group, phenethyl group, and naphthylmethyl group.

R ¹ is preferably a chain hydrocarbon group, more preferably an alkyl group, still more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group, an ethyl group, and an i-propyl group.

R ⁵ and R ⁶ are preferably a chain hydrocarbon group, more preferably an alkyl group, still more preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.

R ⁷ is preferably a chain hydrocarbon group, more preferably an alkyl group, still more preferably an alkyl group having 1 to 5 carbon atoms, and particularly preferably a methyl group and an ethyl group.

Examples of the trivalent chain hydrocarbon group having 1 to 20 carbon atoms represented by R ² , R ³ , R ⁸ and R ⁹ include 1 represented by the above R ¹ , R ⁵ , R ⁶ and R ^7. And groups obtained by removing two hydrogen atoms from a valent chain hydrocarbon group.

Examples of the trivalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ² , R ³ , R ⁸ and R ⁹ include those represented by the above R ¹ , R ⁵ , R ⁶ and R ^7. And a group obtained by removing two hydrogen atoms from a monovalent alicyclic hydrocarbon group.

R ² is preferably an alkanetriyl group and a trivalent alicyclic saturated hydrocarbon group, more preferably a trivalent alicyclic saturated hydrocarbon group, and even more preferably a cyclohexanetriyl group.

R ³ is preferably an alkanetriyl group, more preferably an ethanetriyl group.

R ⁸ is preferably an alkanetriyl group, and more preferably a pentanetriyl group.

R ⁹ is preferably an alkanetriyl group, more preferably an ethanetriyl group.

Examples of the divalent chain hydrocarbon group having 1 or 2 carbon atoms represented by R ⁴ and R ¹⁰ include a methanediyl group, a 1,2-ethanediyl group, and a 1,2-ethenediyl group.

  Examples of the substituent of the divalent chain hydrocarbon group having 1 or 2 carbon atoms include an alkyl group, a halogen atom, a hydroxy group, a nitro group, and a cyano group.

R ⁴ is preferably a methanediyl group.

R ¹⁰ is preferably a methanediyl group.

Examples of the alicyclic structure having 5 to 20 ring members formed together with the carbon atom to which R ⁷ and R ⁸ are combined and R ⁷ is bonded, and R ⁸ , R ⁹ and R ¹⁰ include, for example, a norbornane ring structure and an adamantane ring structure , Tricyclodecane ring structure, tetracyclododecane ring structure and the like. Of these, an adamantane ring structure is preferred.

  Examples of the acid dissociable group (I) include a group represented by the following formula.

In the above formula, * ¹ and * ² each independently represent a bonding site to a moiety other than the acid dissociable group (I) in the structural unit (I).

  Among these, a group having an adamantane ring is preferable, a 2-alkyladamantan-2-yl group and a (adamantan-1-yl) alkane-yl group are more preferable, a 2-methyladamantan-1-yl group, 2- More preferred are an ethyladamantan-2-yl group, a 2-i-propyladamantan-2-yl group, and a 2- (adamantan-1-yl) propan-2-yl group, and a 2-i-propyladamantan-2-yl group. Is particularly preferred.

  Examples of the structural unit (I) include a structural unit represented by the following formula (3-1).

In the formula ^{(3-1), R 14} is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Z ¹ is the acid dissociable group (I).

  As the structural unit (I), a structural unit derived from 2-alkyladamantan-2-yl (meth) acrylate and a structural unit derived from (adamantan-1-yl) alkane-yl (meth) acrylate are preferable. Structural unit derived from methyladamantan-2-yl (meth) acrylate, structural unit derived from 2-ethyladamantan-2-yl (meth) acrylate, derived from 2-i-propyladamantan-2-yl (meth) acrylate And a structural unit derived from 2- (adamantan-1-yl) propan-2-yl (meth) acrylate is more preferred, and a structural unit derived from 2-i-propyladamantan-2-yl (meth) acrylate Is particularly preferred.

  As a minimum of the content rate of structural unit (I), 5 mol% is preferable with respect to all the structural units which comprise a [A] polymer component, 10 mol% is more preferable, 20 mol% is further more preferable, 30 Mole% is particularly preferred. As an upper limit of the said content rate, 80 mol% is preferable, 70 mol% is more preferable, 60 mol% is further more preferable, 55 mol% is especially preferable.

[Structural unit (II)]
The structural unit (II) is a structural unit containing an acid dissociable group (II).

(Acid-dissociable group (II))
The acid dissociable group (II) is an acid dissociable group other than the acid dissociable group (I). Examples of the acid dissociable group (II) include an acid dissociable group represented by the following formula (2).

In the above formula (2), R ¹¹ represents a monovalent chain hydrocarbon group or a monovalent alicyclic hydrocarbon group having a single ring having 3 to 20 carbon atoms having 1 to 20 carbon atoms. R ¹² and R ¹³ are each independently a monovalent chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent monocyclic alicyclic hydrocarbon group having 3 to 10 carbon atoms, or It represents a monocyclic alicyclic structure having 3 to 10 ring members composed of carbon atoms to which these groups are combined with each other. * ³ represents a binding site to a moiety other than the group represented by the formula (2) in the second structural unit.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms represented by R ¹¹ , R ¹² and R ¹³ include, for example, 1 to 1 carbon atoms represented by the above R ¹ , R ⁵ , R ⁶ and R ⁷ . Examples thereof include the same groups as those exemplified as the 20 monovalent chain hydrocarbon group.

Examples of the monovalent monocyclic alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ¹¹ , R ¹² and R ¹³ include those represented by the above R ¹ , R ⁵ , R ⁶ and R ^7. Among those exemplified as the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monocyclic group and the like can be given.

Examples of the monocyclic alicyclic structure having 3 to 10 ring members constituted by the carbon atoms to which the groups of R ¹² and R ¹³ are combined and bonded to each other include, for example, a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, and a cyclohexane structure Monocyclic saturated alicyclic structures such as cycloheptane structure, cyclooctane structure, cyclodecane structure;
And monocyclic unsaturated alicyclic structures such as a cyclopropene structure, a cyclobutene structure, a cyclopentene structure, a cyclohexene structure, a cycloheptene structure, a cyclooctene structure, and a cyclodecene structure.

  Examples of the acid dissociable group (II) include a group represented by the following formula.

In the above formula, * ³ represents a binding site to a moiety other than the acid dissociable group (II) in the structural unit (II).

  The acid-dissociable group (II) is preferably a 1-alkyl-substituted monocyclic monovalent alicyclic saturated hydrocarbon group, such as a 1-alkylcyclopentan-1-yl group or 1-alkylcyclohexane-1-yl. Group and 1-alkylcyclooctan-1-yl group are preferable, 1-methylcyclopentan-1-yl group, 1-ethylcyclopentan-1-yl group, 1-i-propylcyclopentan-1-yl group, 1-t-butylcyclopentan-1-yl group, 1-methylcyclohexane-1-yl group, 1-ethylcyclohexane-1-yl group, 1-i-propylcyclohexane-1-yl group and 1-ethylcyclooctane A -1-yl group is more preferred.

  Examples of the structural unit (II) include a structural unit represented by the following formula (3-2).

In the formula ^{(3-2), R 15} is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Z ² is the acid dissociable group (II).

  As the structural unit (II), a structural unit derived from a (meth) acrylate of a monocyclic monovalent alicyclic saturated hydrocarbon group having 1-alkyl substitution is preferable, and 1-alkylcyclopentan-1-yl (meta ) A structural unit derived from acrylate, a structural unit derived from 1-alkylcyclohexane-1-yl (meth) acrylate, and a structural unit derived from 1-alkylcyclooctane-1-yl (meth) acrylate are more preferred, Structural units derived from methylcyclopentan-1-yl (meth) acrylate, structural units derived from 1-ethylcyclopentan-1-yl (meth) acrylate, 1-i-propylcyclopentan-1-yl (meth) Structural unit derived from acrylate, derived from 1-t-butylcyclopentan-1-yl (meth) acrylate Structural unit, structural unit derived from 1-methylcyclohexane-1-yl (meth) acrylate, structural unit derived from 1-ethylcyclohexane-1-yl (meth) acrylate, 1-i-propylcyclohexane-1-yl ( More preferred are structural units derived from (meth) acrylates and structural units derived from 1-ethylcyclooctane-1-yl (meth) acrylate.

  As a minimum of the content rate of structural unit (II), 5 mol% is preferable with respect to all the structural units which comprise a [A] polymer component, 10 mol% is more preferable, 20 mol% is further more preferable, 30 Mole% is particularly preferred. As an upper limit of the said content rate, 80 mol% is preferable, 70 mol% is more preferable, 60 mol% is further more preferable, 55 mol% is especially preferable.

  [A] The lower limit of the content ratio of the structural unit (I) to the total of the structural unit (I) and the structural unit (II) in the polymer component is 5 mol%, preferably 7 mol%, preferably 9 mol%. More preferably, 10 mol% is further more preferable, and 20 mol% is especially preferable. As an upper limit of the said content rate, it is 80 mol%, 76 mol% is preferable, 72 mol% is more preferable, 70 mol% is further more preferable, 60 mol% is especially preferable. By making the said content rate into the said range, the DOF performance in ISO-TAP pattern formation improves more.

  When the radiation sensitive resin composition contains the [A2] polymer as the [A] polymer component, the [A2] polymer has the structural unit (I) and / or the structural unit (II). Defect suppression of the radiation resin composition can be further improved.

  When the radiation sensitive resin composition contains the [A2] polymer as the [A] polymer component, the lower limit of the total content ratio of the structural unit (I) and the structural unit (II) in the [A2] polymer Is preferably 10 mol%, more preferably 20 mol%, still more preferably 50 mol%, based on all structural units constituting the [A2] polymer. As an upper limit of the said content rate, 90 mol% is preferable, 80 mol% is more preferable, and 75 mol% is further more preferable. [A2] By setting the total content ratio of the structural unit (I) and the structural unit (II) in the polymer within the above range, the defect suppression property of the radiation-sensitive resin composition can be further improved.

[Structural unit (III)]
The structural unit (III) is a structural unit including a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof. [A] The polymer component further includes the structural unit (III) in addition to the structural unit (I) and the structural unit (II), so that the resist pattern formed from the radiation-sensitive resin composition and the substrate Adhesion can be improved.

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

In the above formula, R ^L1 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

  The structural unit (III) is preferably a structural unit containing a γ-butyrolactone structure, a structural unit containing a norbornane lactone structure, a structural unit containing an oxanorbornane structure, a structural unit containing an ethylene carbonate structure, or a structural unit containing a norbornane sultone structure. , Structural unit derived from γ-butyrolactone-yl (meth) acrylate, structural unit derived from norbornanelactone-yl (meth) acrylate, structural unit derived from cyanonorbornanelactone-yl (meth) acrylate, oxanorbornane lactone-yl Structural unit derived from (meth) acrylate, structural unit derived from ethylene carbonate-ylmethyl (meth) acrylate, structural unit derived from norbornane sultone-yl (meth) acrylate, and norbornane lact A structural unit derived from n-yloxycarbonylmethyl (meth) acrylate is more preferred.

  [A] When the polymer component has the structural unit (III), the lower limit of the content ratio of the structural unit (III) is preferably 10 mol% with respect to all the structural units constituting the [A] polymer component. , 20 mol% is more preferable, 30 mol% is more preferable, and 40 mol% is particularly preferable. As an upper limit of the said content rate, 80 mol% is preferable, 70 mol% is more preferable, 65 mol% is further more preferable, 60 mol% is especially preferable. By making the content rate of structural unit (III) into the said range, the adhesiveness of a resist pattern and a board | substrate can be improved more.

[Structural unit (IV)]
The structural unit (IV) is a structural unit containing an alcoholic hydroxyl group. [A] A polymer component can adjust the solubility to a developing solution by having structural unit (IV).

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

In the above formula, R ^L2 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

  As the structural unit (IV), a structural unit containing a hydroxyadamantyl group and a structural unit containing a hydroxyethoxyadamantyl group are preferable, and a structural unit derived from 3-hydroxyadamantan-1-yl (meth) acrylate and 3- (hydroxyethoxy) ) A structural unit derived from adamantane-1-yl (meth) acrylate is more preferred.

  [A] When the polymer component has a structural unit (IV), the lower limit of the content ratio of the structural unit (IV) is preferably 1 mol% with respect to all the structural units constituting the [A] polymer component. 2 mol% is more preferable, 3 mol% is further more preferable, and 5 mol% is especially preferable. As an upper limit of the said content rate, 30 mol% is preferable, 20 mol% is more preferable, 15 mol% is further more preferable, and 10 mol% is especially preferable. By making the content rate of structural unit (IV) into the said range, the [A] polymer component can adjust the solubility to a developing solution more.

[Structural unit (F)]
[A] The fluorine atom contained in the polymer component, particularly in the [A2] polymer, may be bonded to any of the main chain, side chain, and terminal, but is a structural unit containing a fluorine atom (hereinafter referred to as “ It is preferable to have a structural unit (F) ”.

  As the structural unit (F), a structural unit represented by the following formula (f-1) (hereinafter also referred to as “structural unit (F-1)”) and a structural unit represented by the following formula (f-2) (Hereinafter also referred to as “structural unit (F-2)”) is preferable. The structural unit (F) may have one or more structural units (F-1) and structural units (F-2).

[Structural unit (F-1)]
The structural unit (F-1) is a structural unit represented by the following formula (f-1). [A2] The polymer can have a structural unit (F-1) to adjust the mass content of fluorine atoms.

In the above formula (f-1), R ^A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. G is a single bond, an oxygen atom, a sulfur atom, —COO—, —SO ₂ ONH—, —CONH— or —OCONH—. R ^B is a monovalent fluorine-cycloaliphatic hydrocarbon group having a monovalent fluorinated chain hydrocarbon group or a 4 to 20 carbon atoms having 1 to 6 carbon atoms.

^RA is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoint of the copolymerizability of the monomer that provides the structural unit (F-1).

As G, —COO—, —SO ₂ ONH—, —CONH— and —OCONH— are preferable, and —COO— is more preferable.

The monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms represented by R ^B, such as trifluoromethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 2,2 , 3,3,3-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoropropyl group, perfluoro n-propyl group, perfluoro i-propyl group, perfluoro n-butyl group, Examples include perfluoro i-butyl group, perfluoro t-butyl group, 2,2,3,3,4,4,5,5-octafluoropentyl group, perfluorohexyl group and the like.

The monovalent fluorine-cycloaliphatic hydrocarbon group having 4 to 20 carbon atoms represented by R ^B, for example, monofluoromethyl cyclopentyl group, difluorocyclopentyl groups, perfluorocyclopentyl group, monofluoromethyl cyclohexyl group, difluorocyclopentyl groups Perfluorocyclohexylmethyl group, fluoronorbornyl group, fluoroadamantyl group, fluorobornyl group, fluoroisobornyl group, fluorotricyclodecyl group, fluorotetracyclodecyl group and the like.

The R ^B, preferably a fluorinated chain hydrocarbon group, a 2,2,2-trifluoroethyl group and 1,1,1,3,3,3-hexafluoro-2-propyl group is more preferred, 2 2,2-trifluoroethyl group is more preferable.

  [A2] When a polymer has a structural unit (F-1), as a minimum of the content rate of a structural unit (F-1), it is 10 mol% with respect to all the structural units which comprise a [A2] polymer. Is preferable, and 20 mol% is more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 70 mol% is more preferable, and 50 mol% is further more preferable. By making the content rate of a structural unit (F-1) into the said range, the mass content rate of the fluorine atom of a [A2] polymer can be adjusted further appropriately.

[Structural unit (F-2)]
The structural unit (F-2) is a structural unit represented by the following formula (f-2). [A2] Since the polymer has the structural unit (F-2), the mass content of fluorine atoms can be adjusted, and the resist film surface can be changed from water-repellent to hydrophilic before and after alkali development.

In the above formula (f-2), R ^C represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^D is an (s + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, or an oxygen atom, a sulfur atom, —NR′—, a carbonyl group, —COO—, or — at the terminal on the R ^E side of this hydrocarbon group. It is a structure in which CONH- is bonded. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^E is a single bond or a divalent organic group having 1 to 20 carbon atoms. W ¹ is a single bond or a divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms. A ¹ is an oxygen atom, —NR ″ —, —COO— *, or —SO ₂ O— *. R ″ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. * Indicates a site binding to ^{R F.} R ^F is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms. s is an integer of 1 to 3. However, when s is 1, ^RD may be a single bond. When s is 2 or 3, a plurality of R ^E , W ¹ , A ¹ and R ^F may be the same or different. When W ¹ is a single bond, R ^F is a group containing a fluorine atom.

As R ^C , a hydrogen atom and a methyl group are preferable, and a methyl group is more preferable from the viewpoint of copolymerizability of the monomer that gives the structural unit (F-2).

Examples of the (s + 1) -valent hydrocarbon group having 1 to 20 carbon atoms represented by ^RD include, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms exemplified as R ^{6 to} R ^{8 in} the above formula (2). A group obtained by removing s hydrogen atoms from

  As s, 1 and 2 are preferable and 1 is more preferable.

As ^RD , when s is 1, a single bond and a divalent hydrocarbon group are preferable, a single bond and an alkanediyl group are more preferable, a single bond and an alkanediyl group having 1 to 4 carbon atoms are more preferable, Bonds, methanediyl groups and propanediyl groups are particularly preferred.

Divalent organic groups, for example a divalent exemplified those same groups as organic groups of formula (2 ') carbon atoms of L ¹ to 20 having 1 to 20 carbon atoms represented by R ^E Etc.

R ^E is preferably a group having a single bond and a lactone structure, more preferably a group having a single bond and a polycyclic lactone structure, and more preferably a group having a single bond and a norbornane lactone structure.

Examples of the divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms represented by W ¹ include a fluoromethanediyl group, a difluoromethanediyl group, a fluoroethanediyl group, a difluoroethanediyl group, and a tetrafluoroethanediyl group. Fluorinated alkanediyl groups such as hexafluoropropanediyl group, octafluorobutanediyl group;
Examples thereof include fluorinated alkenediyl groups such as a fluoroethenediyl group and a difluoroethenediyl group. Among these, a fluorinated alkanediyl group is preferable, and a difluoromethanediyl group is more preferable.

The A ^1, an oxygen _{atom, -COO - *, - SO 2} O- * are preferable, -COO- * is more preferable.

The monovalent organic group having 1 to 30 carbon atoms represented by R ^F, for example, an alkali dissociative group, the acid-dissociable group, and the like hydrocarbon group having 1 to 30 carbon atoms. Of these, as R ^F , an alkali dissociable group is preferable. By the R ^F and alkali-labile group, upon alkali development, the resist film surface it is possible to effectively alter the hydrophilicity of hydrophobic, defect suppression of the radiation-sensitive resin composition is further improved.

When R ^F is an alkali-dissociable group, R ^F is preferably a group represented by the following formulas (iii) to (v) (hereinafter also referred to as “groups (iii) to (v)”).

In the above formula (iii), R ^5a and R ^5b are each independently a monovalent organic group having 1 to 20 carbon atoms, or these groups are combined with each other to form a carbon atom to which they are bonded. Represents an alicyclic structure having 3 to 20 ring members.

In the above formula (iv), R ^5c and R ^5d are each independently a monovalent organic group having 1 to 20 carbon atoms, or these groups are combined with each other to form a nitrogen atom to which they are bonded. Represents a heterocyclic structure having 3 to 20 ring members.

In the above formula (v), R ^5e is a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms.

Examples of the monovalent organic group having 1 to 20 carbon atoms and the monovalent hydrocarbon group having 1 to 20 carbon atoms include groups similar to those exemplified as R ^{2 in the} above formula (I).

  As the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms, for example, part or all of the hydrogen atoms of the group exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms are substituted with fluorine atoms. And the like.

  As the group (iii), groups represented by the following formulas (iii-1) to (iii-4) (hereinafter also referred to as “groups (iii-1) to (iii-4)”) are represented by the group (iv) Is a group represented by the following formula (iv-1) (hereinafter also referred to as “group (iv-1)”), and the group (v) is represented by the following formulas (v-1) to (v-5): The groups represented (hereinafter also referred to as “groups (v-1) to (v-5)”) are preferable.

  Among these, group (v-3) and group (v-5) are preferable.

Moreover, it is preferable that ^RF is a hydrogen atom because the affinity of the [A2] polymer for an alkaline developer is improved. In this case, when A ¹ is an oxygen atom and W ¹ is a 1,1,1,3,3,3-hexafluoro-2,2-methanediyl group, the affinity is further improved.

  [A2] When the polymer has a structural unit (F-2), the lower limit of the content ratio of the structural unit (F-2) is 10 mol% with respect to all the structural units constituting the [A2] polymer. Is preferable, 20 mol% is more preferable, and 40 mol% is further more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 85 mol% is more preferable, and 80 mol% is further more preferable. By setting the content ratio of the structural unit (F-2) in the above range, the surface of the resist film formed from the radiation-sensitive resin composition can be more appropriately changed from water repellency to hydrophilicity before and after alkali development. .

  As a minimum of the content rate of a structural unit (F), 10 mol% is preferable with respect to all the structural units which comprise a [A2] polymer, 20 mol% is more preferable, and 25 mol% is further more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 85 mol% is more preferable, and 80 mol% is further more preferable.

  [A2] The polymer preferably has an alkali dissociable group. [A2] When the polymer has an alkali-dissociable group, the resist film surface can be effectively changed from hydrophobic to hydrophilic during alkali development, and defect suppression of the radiation-sensitive resin composition is further improved. . The “alkali dissociable group” is a group that replaces a hydrogen atom such as a carboxy group or a hydroxy group, and is a group that dissociates in an alkaline aqueous solution (eg, 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C.). Say.

  When the radiation sensitive resin composition contains the [A2] polymer in addition to the [A1] polymer, the lower limit of the content of the [A2] polymer is 100 parts by mass of the [A1] polymer. 0.1 parts by mass is preferable, 0.5 parts by mass is more preferable, 1 part by mass is further preferable, and 2 parts by mass is particularly preferable. As an upper limit of the said content, 30 mass parts is preferable, 20 mass parts is more preferable, 15 mass parts is further more preferable, and 10 mass parts is especially preferable. The radiation-sensitive resin composition may contain one or more [A1] polymers and [A2] polymers.

[Other structural units]
[A] The polymer component may have other structural units in addition to the structural units (I) to (IV) and the structural unit (F). Examples of the other structural unit include a structural unit containing a ketonic carbonyl group, a cyano group, a carboxy group, a nitro group, an amino group or a combination thereof, a structural unit containing a phenolic hydroxyl group, and a non-dissociative monovalent fat. Examples include a structural unit derived from a (meth) acrylic acid ester containing a cyclic hydrocarbon group. As an upper limit of the content rate of another structural unit, 20 mol% is preferable with respect to all the structural units which comprise a [A] polymer component, and 10 mol% is more preferable.

  [A] The lower limit of the content of the polymer component is preferably 70% by mass, more preferably 80% by mass, and still more preferably 85% by mass with respect to the total solid content of the radiation-sensitive resin composition. “Total solid content” refers to the sum of components other than the solvent [C] in the radiation-sensitive resin composition. The radiation-sensitive resin composition may contain one or more [A] polymer components. [A1] The preferred range of the content of the polymer is the same as the content of the above [A] polymer component.

<[A] Polymer component synthesis method>
[A] Each polymer constituting the polymer component can be synthesized, for example, by polymerizing monomers that give each structural unit in a suitable solvent using a radical polymerization initiator or the like.

Examples of the radical polymerization initiator include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropyl). Azo radical initiators such as propionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2′-azobisisobutyrate;
And peroxide radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, and the like. Of these, AIBN and dimethyl 2,2′-azobisisobutyrate are preferred, and AIBN is more preferred. These radical polymerization initiators can be used alone or in combination of two or more.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane;
Cycloaliphatic hydrocarbons such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane;
Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene;
Halogenated hydrocarbons such as chlorobutane, bromohexane, dichloroethane, hexamethylene dibromide, chlorobenzene;
Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate;
Ketones such as acetone, methyl ethyl ketone, 4-methyl-2-pentanone, 2-heptanone;
Ethers such as tetrahydrofuran, dimethoxyethanes, diethoxyethanes;
Examples include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol. The solvent used for these polymerizations may be used alone or in combination of two or more.

  As a minimum of reaction temperature in superposition | polymerization, 40 degreeC is preferable and 50 degreeC is more preferable. As an upper limit of the said reaction temperature, 150 degreeC is preferable and 120 degreeC is more preferable. As a minimum of reaction time in superposition | polymerization, 1 hour is preferable and 2 hours is more preferable. The upper limit of the reaction time is preferably 48 hours, more preferably 24 hours.

  [A] As a minimum of polystyrene conversion weight average molecular weight (Mw) by gel permeation chromatography (GPC) of a polymer component, 1,000 is preferred, 3,000 is more preferred, 4,000 is still more preferred, and 5 Is particularly preferred. The upper limit of Mw is preferably 50,000, more preferably 30,000, still more preferably 20,000, and particularly preferably 10,000. [A] By making Mw of a polymer component into the said range, the coating property of the said radiation sensitive resin composition can be improved, As a result, DOF performance in ISO-TAP pattern formation is improved more. Can do.

  [A] The lower limit of the Mw ratio (Mw / Mn) to the number average molecular weight (Mn) in terms of polystyrene by GPC of the polymer component is usually 1 and preferably 1.1. As an upper limit of the ratio, 5 is preferable, 3 is more preferable, 2 is more preferable, and 1.5 is particularly preferable.

  The preferable ranges of Mw and Mw / Mn of the [A1] polymer and [A2] polymer are the same as the preferable ranges of Mw and Mw / Mn of the [A] polymer component.

Mw and Mn of the polymer component or polymer in the present specification are values measured using GPC under the following conditions.
GPC column: For example, two “G2000HXL”, one “G3000HXL” and one “G4000HXL” manufactured by Tosoh Corporation Column temperature: 40 ° C.
Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

<[B] Acid generator>
[B] The acid generator is a substance that generates an acid upon exposure. The generated acid causes the acid dissociable group (I) and the acid dissociable group (II) of the [A] polymer component to dissociate to produce a carboxy group, a hydroxy group, etc., and develop the [A] polymer component. Since the solubility in the liquid changes, a resist pattern can be formed from the radiation-sensitive resin composition. In the radiation sensitive resin composition, the [B] acid generator is incorporated as a part of the polymer even in the form of a low molecular compound (hereinafter also referred to as “[B] acid generator” as appropriate). Either of these forms may be used.

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

  Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.

  [B] Specific examples of the acid generator include compounds described in paragraphs [0080] to [0113] of JP-A-2009-134088.

  [B] Examples of the acid generated from the acid generator include sulfonic acid, imidic acid, amide acid, methide acid, phosphinic acid, and carboxylic acid. Of these, sulfonic acid, imidic acid, amic acid and methide acid are preferred.

  Examples of the [B] acid generator include a compound represented by the following formula (4) (hereinafter also referred to as “[B1] acid generator”).

In the above formula (4), A ⁻ represents a monovalent sulfonate anion, a monovalent imido acid anion, a monovalent amidate anion, or a monovalent methide acid anion. Z ⁺ is a monovalent radiation-sensitive onium cation.

[B1] acid generator, A in the above formula (4) ^- if the sulfonate anion (hereinafter, "[B1a]" acid generator) also called), a sulfonic acid is generated. A ^- is the case of the imide anion (hereinafter, also referred to as "[B1b] acid generator"), imide acid produced. A ^- is the case of the amide anion (hereinafter, also referred to as "[B1c] acid generator"), an amide acid occurs. A ^- is the case of the methide anion (hereinafter, also referred to as "[B1d] acid generator"), methide acid is generated.

  [B1a] Examples of the acid generator include a compound represented by the following formula (4-1) (hereinafter also referred to as “compound (4-1)”). [B1] Since the acid generator has the following structure, [A] Diffusion of acid generated by exposure in the resist film due to the interaction between the structural unit (I) and the structural unit (II) of the polymer component The length is considered to be appropriately shortened, and as a result, the LWR performance and the like of the radiation-sensitive resin composition can be further improved.

In the above formula (4-1), R ^p1 is a monovalent group containing a ring structure having 6 or more ring members. R ^p2 is a divalent linking group. R ^p3 and R ^p4 are each independently a hydrogen atom, a fluorine atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. R ^p5 and R ^p6 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. n ^p1 is an integer of 0 to 10. n ^p2 is an integer of 0 to 10. n ^p3 is an integer of 0 to 10. However, n ^p1 + n ^p2 + n ^p3 is 1 or more and 30 or less. When n ^p1 is 2 or more, the plurality of R ^p2 may be the same or different. When n ^p2 is 2 or more, the plurality of R ^p3 may be the same or different, and the plurality of R ^p4 may be the same or different. When n ^p3 is 2 or more, the plurality of R ^p5 may be the same or different, and the plurality of R ^p6 may be the same or different. Z ⁺ has the same ^{meaning as} in the above formula (3).

Examples of the monovalent group including a ring structure having 6 or more ring members represented by R ^p1 include a monovalent group including an alicyclic structure having 6 or more ring members and an aliphatic heterocyclic structure having 6 or more ring members. A monovalent group, a monovalent group containing an aromatic ring structure having 6 or more ring members, a monovalent group containing an aromatic heterocyclic structure having 6 or more ring members, and the like.

Examples of the alicyclic structure having 6 or more ring members include monocyclic saturated alicyclic structures such as a cyclohexane structure, a cycloheptane structure, a cyclooctane structure, a cyclononane structure, a cyclodecane structure, and a cyclododecane structure;
Monocyclic unsaturated alicyclic structures such as cyclohexene structure, cycloheptene structure, cyclooctene structure, cyclodecene structure;
Polycyclic saturated alicyclic structures such as norbornane structure, adamantane structure, tricyclodecane structure and tetracyclododecane structure;
Examples thereof include polycyclic unsaturated alicyclic structures such as a norbornene structure and a tricyclodecene structure.

Examples of the aliphatic heterocyclic structure having 6 or more ring members include lactone structures such as a hexanolactone structure and a norbornane lactone structure;
Sultone structures such as hexanosultone structure and norbornane sultone structure;
An oxygen atom-containing heterocyclic structure such as an oxacycloheptane structure or an oxanorbornane structure;
Nitrogen atom-containing heterocyclic structures such as azacyclohexane structure and diazabicyclooctane structure;
Examples thereof include a sulfur atom-containing heterocyclic structure having a thiacyclohexane structure and a thianorbornane structure.

Examples of the aromatic ring structure having 6 or more ring members include a benzene structure, a naphthalene structure, a phenanthrene structure, and an anthracene structure.

Examples of aromatic heterocyclic structures having 6 or more ring members include oxygen atom-containing heterocyclic structures such as furan structures, pyran structures, and benzopyran structures;
Examples thereof include a nitrogen atom-containing heterocyclic structure such as a pyridine structure, a pyrimidine structure and an indole structure.

The lower limit of the number of ring members of the ring structure of R ^p1 is preferably 7, more preferably 8, more preferably 9, and particularly preferably 10. The upper limit of the number of ring members is preferably 15, more preferably 14, more preferably 13, and particularly preferably 12. By setting the number of ring members in the above range, the acid diffusion length can be further appropriately shortened, and as a result, the LWR performance and the like of the radiation-sensitive resin composition can be further improved.

A part or all of the hydrogen atoms ^{contained in} the ring structure of R ^p1 may be substituted with a substituent. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, nitro group, alkoxy group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, Examples include an acyloxy group. Of these, a hydroxy group is preferred.

R ^p1 is preferably a monovalent group containing an alicyclic structure having 6 or more ring members and a monovalent group containing an aliphatic heterocyclic structure having 6 or more ring members, and 1 containing an alicyclic structure having 9 or more ring members. And a monovalent group containing an aliphatic heterocyclic structure having 9 or more ring members, an adamantyl group, a hydroxyadamantyl group, a norbornane lactone-yl group, a norbornane sultone-yl group, and 5-oxo-4-oxa A tricyclo [4.3.1.1 ^3,8 ] undecan-yl group is more preferred, and an adamantyl group is particularly preferred.

Examples of the divalent linking group represented by R ^p2 include a carbonyl group, an ether group, a carbonyloxy group, a sulfide group, a thiocarbonyl group, a sulfonyl group, and a divalent hydrocarbon group. Among these, a carbonyloxy group, a sulfonyl group, an alkanediyl group and a divalent alicyclic saturated hydrocarbon group are preferable, a carbonyloxy group and a divalent alicyclic saturated hydrocarbon group are more preferable, and a carbonyloxy group And a norbornanediyl group are more preferable, and a carbonyloxy group is particularly preferable.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^p3 and R ^p4 include an alkyl group having 1 to 20 carbon atoms. Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ^p3 and R ^p4 include a fluorinated alkyl group having 1 to 20 carbon atoms. R ^p3 and R ^p4 are preferably a hydrogen atom, a fluorine atom and a fluorinated alkyl group, more preferably a fluorine atom and a perfluoroalkyl group, and still more preferably a fluorine atom and a trifluoromethyl group.

Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ^p5 and R ^p6 include a fluorinated alkyl group having 1 to 20 carbon atoms. R ^p5 and R ^p6 are preferably a fluorine atom and a fluorinated alkyl group, more preferably a fluorine atom and a perfluoroalkyl group, still more preferably a fluorine atom and a trifluoromethyl group, and particularly preferably a fluorine atom.

The n ^p1, preferably an integer of 0 to 5, more preferably an integer of 0 to 3, more preferably an integer of 0 to 2, 0 and 1 are particularly preferred.

The n ^p2, preferably an integer of 0 to 5, more preferably an integer of 0 to 2, more preferably 0 and 1, 0 being particularly preferred.

As a minimum of ^np3 , 1 is preferable and 2 is more preferable. By setting n ^p3 to 1 or more, the strength of the acid generated from the compound (4-1) can be increased, and as a result, the LWR performance and the like of the radiation-sensitive resin composition can be further improved. The upper limit of n ^p3 is preferably 4, more preferably 3, and even more preferably 2.

The lower limit of n ^p1 + n ^p2 + n ^p3 is preferably 2 and more preferably 4. The upper limit of n ^p1 + n ^p2 + n ^p3 is preferably 20, and more preferably 10.

Examples of the monovalent radiation-sensitive onium cation represented by Z ⁺ include cations represented by the following formulas (Z-1) to (Z-3) (hereinafter referred to as “cations (Z-1) to (Z−)”. 3) ")) and the like.

In the formula (Z-1), R ^a1 , R ^a2 and R ^a3 each independently represent a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 12 carbon atoms. family hydrocarbon group, two or more are combined with each other configured ring structure of either a -OSO ₂ -R ^P or _-SO 2 -R ^Q, or their groups. R ^P and R ^Q are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted carbon. It is an aromatic hydrocarbon group of formula 6-12. k1, k2 and k3 are each independently an integer of 0 to 5. R ^a1 to R ^a3 and when ^{R P} and ^{R Q} are a plurality each of the plurality of ^R a1 ^{to R a3} and ^{R P} and ^{R Q} may be the same as or different from each other.

In the above formula (Z-2), R ^a4 is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms. k4 is an integer of 0 to 7. If R ^a4 is plural, the plurality of R ^a4 may be the same or different, and plural R ^a4 may represent a constructed ring aligned with each other. R ^a5 is a substituted or unsubstituted alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms. k5 is an integer of 0-6. If R ^a5 is plural, the plurality of R ^a5 may be the same or different, and plural R ^a5 may represent a keyed configured ring structure. r is an integer of 0-3. R ^a6 is a single bond or a divalent organic group having 1 to 20 carbon atoms. t is an integer of 0-2.

In the above formula (Z-3), R ^a7 and R ^a8 are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon having 6 to 12 carbon atoms. group, or an -OSO ₂ -R ^R or _-SO 2 -R ^S, or two or more are combined with each other configured ring of these groups. R ^R and R ^S are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted carbon. It is an aromatic hydrocarbon group of formula 6-12. k6 and k7 are each independently an integer of 0 to 5. R ^{a7, R} a8, ^R when ^R and ^{R S} is plural respective plurality of ^{R a7,} R a8, ^{R R} and ^{R S} may be the same as or different from each other.

Examples of the alkyl group represented by R ^{a1 to} R ^a3 , R ^a4 , R ^a5 , R ^a7 and R ^a8 include linear alkyl groups such as a methyl group, an ethyl group, an n-propyl group, and an n-butyl group;
Examples thereof include branched alkyl groups such as i-propyl group, i-butyl group, sec-butyl group and t-butyl group.

Examples of the aromatic hydrocarbon group represented by R ^{a1 to} R ^a3 , R ^a4 and R ^a5 include aryl groups such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, and a naphthyl group;
Examples include aralkyl groups such as benzyl group and phenethyl group.

Examples of the aromatic hydrocarbon group represented by R ^a4 and R ^a5 include a phenyl group, a tolyl group, and a benzyl group.

Examples of the divalent organic group represented by R ^a6 include a group obtained by removing one hydrogen atom from the monovalent organic group represented by R ^{4 in} the above formula (a-3).

  Examples of the substituent for substituting the hydrogen atom of the alkyl group and aromatic hydrocarbon group include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, nitro group, alkoxy Group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, acyloxy group and the like. Among these, a halogen atom is preferable and a fluorine atom is more preferable.

R ^{a1 to} R ^a3 , R ^a4 , R ^a5 , R ^a7 and R ^a8 include an unsubstituted alkyl group, a fluorinated alkyl group, an unsubstituted monovalent aromatic hydrocarbon group, —OSO ₂ —R ″ and —SO ₂ —R ″ is preferable, a fluorinated alkyl group and an unsubstituted monovalent aromatic hydrocarbon group are more preferable, and a fluorinated alkyl group is further preferable. R ″ is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

  As k1, k2, and k3 in Formula (Z-1), integers of 0 to 2 are preferable, 0 and 1 are more preferable, and 0 is more preferable. As k4 in Formula (Z-2), an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 1 is more preferable. k5 is preferably an integer of 0 to 2, more preferably 0 and 1, and still more preferably 0. As r, 2 and 3 are preferable, and 2 is more preferable. As t, 0 and 1 are preferable, and 0 is more preferable. As k6 and k7 in Formula (Z-3), an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 0 is more preferable.

Among these, cation (Z-1) and cation (Z-2) are preferable as Z ⁺ , and triphenylsulfonium cation and 4-butoxynaphthalen-1-yltetrahydrothiophenium cation are more preferable.

  [B1a] Examples of the acid generator include compounds represented by the following formulas (4-1-1) to (4-1-19) (hereinafter referred to as “compounds (4-1-1) to (4-1-1)”. 19) ")) and the like. [B1b] Examples of the acid generator include compounds represented by the following formulas (4-2-1) to (4-2-3) (hereinafter referred to as “compounds (4-2-1) to (4-2-2)”. 3) ")) and the like. [B1c] Examples of the acid generator include compounds represented by the following formula (4-3-1) and formula (4-3-2) (hereinafter referred to as “compound (4-3-1), (4-3)”. -2) "). [B1d] Examples of the acid generator include compounds represented by the following formula (4-4-1) and formula (4-4-2) (hereinafter referred to as “compound (4-4-1), (4-4)”. -2) ").

The above formulas (4-1-1) to (4-1-19), (4-2-1) to (4-2-3), (4-3-1), (4-3-2), In (4-4-1) and (4-4-2), Z ⁺ is a monovalent onium cation.

  [B1] As the acid generator, [B1a] acid generator and [B1b] acid generator are preferable, and the compounds (4-1-1), (4-1-3), (4-1-13) and (4-1-16) to (4-1-19) and the compound (4-2-1) are more preferable.

  [B1] As the acid generator, onium salt compounds are preferable, sulfonium salts and tetrahydrothiophenium salts are more preferable, and triphenylsulfonium salts and 4-butoxynaphthalen-1-yltetrahydrothiophenium salts are more preferable.

  [B] The acid generator is also preferably a polymer in which the structure of an acid generator such as a polymer having a structural unit represented by the following formula (4-1 ′) is incorporated as a part of the polymer. .

In the above formula (4-1 ′), R ^p7 represents a hydrogen atom or a methyl group. L ⁴ is a single bond or —COO— or a divalent carbonyloxy hydrocarbon group. R ^p8 is a fluorinated alkanediyl group having 1 to 10 carbon atoms. Z ⁺ is synonymous with the above formula (4).

As R ^p7 , a hydrogen atom and a methyl group are preferable, and a methyl group is more preferable, from the viewpoint of copolymerization of the monomer that gives the structural unit represented by the above formula (4-1 ′).

L ⁴ is preferably a divalent carbonyloxy hydrocarbon group, more preferably a carbonyloxyalkanediyl group or a carbonylalkanediylarenediyl group.

R ^p8 is preferably a fluorinated alkanediyl group having 1 to 4 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 4 carbon atoms, and still more preferably a hexafluoropropanediyl group.

  [B] When the acid generator is a [B] acid generator, the lower limit of the content of the [B] acid generator is preferably 0.1 parts by mass with respect to 100 parts by mass of the [A] polymer component. 0.5 parts by mass is more preferable, 1 part by mass is further preferable, 2 parts by mass is particularly preferable, 3 parts by mass is further particularly preferable, and 5 parts by mass is most preferable. As an upper limit of the said content, 50 mass parts is preferable, 40 mass parts is more preferable, 30 mass parts is further more preferable, 20 mass parts is especially preferable.

  Moreover, as a minimum of content of [B] acid generator, 0.1 mass% is preferable with respect to solid content conversion, ie, the total solid of the said radiation sensitive resin composition, 0.5 mass% is preferable. More preferably, 1% by mass is further preferable, 2% by mass is particularly preferable, 3% by mass is further particularly preferable, and 5% by mass is most preferable. As an upper limit of the said content, 50 mass% is preferable, 40 mass% is more preferable, 30 mass% is further more preferable, 20 mass% is especially preferable.

  [B] By making content of an acid generator into the said range, the sensitivity and developability of the said radiation sensitive resin composition improve, As a result, the DOF performance in ISO-TAP formation can be improved more. . The radiation-sensitive resin composition may contain one or more [B] acid generators.

<[C] solvent>
[C] The solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the [A] polymer component, the [B] acid generator, and other optional components contained as necessary.

  [C] Examples of the solvent include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents, and the like.

Examples of the alcohol solvent include aliphatic monoalcohol solvents having 1 to 18 carbon atoms such as 4-methyl-2-pentanol and n-hexanol;
An alicyclic monoalcohol solvent having 3 to 18 carbon atoms such as cyclohexanol;
A C2-C18 polyhydric alcohol solvent such as 1,2-propylene glycol;
Examples thereof include C3-C19 polyhydric alcohol partial ether solvents such as propylene glycol monomethyl ether.

Examples of ether solvents include dialkyl ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, diisoamyl ether, dihexyl ether, and diheptyl ether;
Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;
And aromatic ring-containing ether solvents such as diphenyl ether and anisole.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, Chain ketone solvents such as di-iso-butyl ketone and trimethylnonanone:
Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and methylcyclohexanone:
2,4-pentanedione, acetonylacetone, acetophenone and the like can be mentioned.

Examples of the amide solvent include cyclic amide solvents such as N, N′-dimethylimidazolidinone and N-methylpyrrolidone;
Examples thereof include chain amide solvents such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, and N-methylpropionamide.

Examples of ester solvents include monocarboxylic acid ester solvents such as n-butyl acetate and ethyl lactate;
Polyhydric alcohol carboxylate solvents such as propylene glycol acetate;
Polyhydric alcohol partial ether carboxylate solvents such as propylene glycol monomethyl ether acetate;
Polycarboxylic acid diester solvents such as diethyl oxalate;
lactone solvents such as γ-butyrolactone and δ-valerolactone;
Examples thereof include carbonate solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate.

Examples of the hydrocarbon solvent include aliphatic hydrocarbon solvents having 5 to 12 carbon atoms such as n-pentane and n-hexane;
Examples thereof include aromatic hydrocarbon solvents having 6 to 16 carbon atoms such as toluene and xylene.

  [C] As the solvent, ester solvents and ketone solvents are preferable, polyhydric alcohol partial ether carboxylate solvents, lactone solvents and cyclic ketone solvents are more preferable, polyhydric alcohol partial alkyl ether acetates, butyrolactones and Cycloalkanones are more preferred, with propylene glycol monomethyl ether acetate, γ-butyrolactone and cyclohexanone being particularly preferred. The radiation-sensitive resin composition may contain one or more [C] solvents.

<[D] Acid diffusion controller>
The said radiation sensitive resin composition may contain a [D] acid diffusion control body as needed. [D] The acid diffusion controller controls the diffusion phenomenon in the resist film of the acid generated from the [B] acid generator by exposure, and has an effect of suppressing an undesirable chemical reaction in the non-exposed region. Further, the storage stability of the radiation sensitive resin composition is improved, and the resolution as a resist is further improved. Furthermore, a change in the line width of the resist pattern due to fluctuations in the holding time from exposure to development processing can be suppressed, and a radiation-sensitive resin composition excellent in process stability can be obtained. [D] The content of the acid diffusion controller in the radiation-sensitive resin composition is incorporated as a part of the polymer even in the form of a free compound (hereinafter referred to as “[D] acid diffusion controller” as appropriate). Or both of these forms.

  [D] As the acid diffusion controller, for example, a compound represented by the following formula (5) (hereinafter also referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound (I)”) "Nitrogen-containing compound (II)"), compounds having three nitrogen atoms (hereinafter also referred to as "nitrogen-containing compound (III)"), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, etc. It is done.

In the above formula (5), R ²⁰ , R ²¹ and R ²² are each independently a hydrogen atom, an optionally substituted linear, branched or cyclic alkyl group, an aryl group or an aralkyl group. .

  Examples of the nitrogen-containing compound (I) include monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine; aromatic amines such as aniline. It is done.

  Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, and the like.

  Examples of the nitrogen-containing compound (III) include polyamine compounds such as polyethyleneimine and polyallylamine; polymers such as dimethylaminoethylacrylamide.

  Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like. It is done.

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

  Examples of the nitrogen-containing heterocyclic compound include pyridines such as pyridine and 2-methylpyridine; morpholines such as N-propylmorpholine and N- (undecylcarbonyloxyethyl) morpholine; pyrazine and pyrazole.

  As the nitrogen-containing organic compound, a compound having an acid dissociable group can also be used. Examples of the nitrogen-containing organic compound having such an acid dissociable group include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2. -Phenylbenzimidazole, N- (t-butoxycarbonyl) di-n-octylamine, N- (t-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) dicyclohexylamine, N- (t-butoxycarbonyl) diphenylamine Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine and the like.

  Further, as the [D] acid diffusion control agent, a photodisintegratable base that is exposed to light and generates a weak acid by exposure can also be used. Examples of the photodegradable base include an onium salt compound that loses acid diffusion controllability by being decomposed by exposure. Examples of the onium salt compound include a sulfonium salt compound represented by the following formula (6-1), an iodonium salt compound represented by the following formula (6-2), and the like.

In the above formulas (6-1) and (6-2), R ^{23 to} R ²⁷ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, or a halogen atom. E ⁻ and Q ⁻ are each independently an anion represented by OH ⁻ , R ^β —COO ⁻ , R ^β —SO ₃ ^— or the following formula (6-3). However, R ( ^beta) is an alkyl group, an aryl group, or an aralkyl group.

In the above formula (6-3), R ²⁸ represents a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched fluorinated alkyl group having 1 to 12 carbon atoms, or 1 carbon atom. -12 linear or branched alkoxy groups. u is an integer of 0-2. When u is 2, two R ²⁸ may be the same or different.

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

  Of these, the photodegradable base is preferably a sulfonium salt, more preferably a triarylsulfonium salt, and even more preferably triphenylsulfonium salicylate and triphenylsulfonium 10-camphorsulfonate.

  When the radiation sensitive resin composition contains a [D] acid diffusion controller as the [D] acid diffusion controller, the lower limit of the content of the [D] acid diffusion controller is the [A] polymer. 0.1 mass part is preferable with respect to 100 mass parts of components, 0.3 mass part is more preferable, and 1 mass part is further more preferable. As an upper limit of the said content, 20 mass parts is preferable, 10 mass parts is more preferable, and 5 mass parts is further more preferable. The radiation-sensitive resin composition may contain one or more [D] acid diffusion controllers.

<Other optional components>
The said radiation sensitive resin composition may contain other arbitrary components other than said [A]-[D] component. Examples of other optional components include polymers other than the above [A1] polymer and [A2] polymer, surfactants, alicyclic skeleton-containing compounds, and sensitizers. Each of these other optional components may be used alone or in combination of two or more.

[Other polymers]
The other polymer is a polymer other than the above [A1] polymer and [A2] polymer. Examples of the other polymer include a polymer other than the above-mentioned [A2] polymer and a polymer having a larger mass content of fluorine atoms than the above-mentioned [A1] polymer. Examples thereof include a polymer having the structural unit (F-1) and / or (F-2) and not having the structural unit (I) and the structural unit (II). The radiation sensitive resin composition containing such a polymer can be suitably used for immersion exposure.

[Surfactant]
Surfactants have the effect of improving coatability, striation, developability, and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol diacrylate. Nonionic surfactants such as stearate; commercially available products include KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, Tochem Products), MegaFuck F171, F173 (above, DIC), Florard FC430, FC431 (above, Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (above, Asahi Glass Industrial Co., Ltd.) Can be mentioned. As an upper limit of content of surfactant, 2 mass parts is preferable with respect to 100 mass parts of [A] polymer components.

[Alicyclic skeleton-containing compound]
The alicyclic skeleton-containing compound has an effect of improving dry etching resistance, pattern shape, adhesion to the substrate, and the like.

Examples of the alicyclic skeleton-containing compound include adamantane derivatives such as 1-adamantanecarboxylic acid, 2-adamantanone, and 1-adamantanecarboxylic acid t-butyl;
Deoxycholic acid esters such as t-butyl deoxycholate, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid;
Lithocholic acid esters such as t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid;
3- [2-Hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, 2-hydroxy-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nonane, and the like. As an upper limit of content of an alicyclic frame | skeleton containing compound in the said radiation sensitive resin composition, 5 mass parts is preferable with respect to 100 mass parts of [A] polymer components.

[Sensitizer]
A sensitizer exhibits the effect | action which increases the production amount of the acid from [B] acid generator etc., and there exists an effect which improves the "apparent sensitivity" of the said radiation sensitive resin composition.

  Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines and the like. As an upper limit of content of the sensitizer in the said radiation sensitive resin composition, 2 mass parts is preferable with respect to 100 mass parts of [A] polymer components.

<Preparation of radiation-sensitive resin composition>
The radiation sensitive resin composition includes, for example, [A] a polymer component, [B] acid generator, [C] solvent, and [D] acid diffusion controller contained as necessary at a predetermined ratio. Preferably, the mixture obtained can be prepared by filtering with a filter having a pore size of about 0.2 μm, for example.

  2. The lower limit of the solid content concentration of the radiation-sensitive resin composition (total of components other than [C] solvent) is 2% by mass, preferably 2.5% by mass, more preferably 3% by mass. 5 mass% is more preferable. The upper limit of the solid content concentration is 6% by mass, preferably 5.5% by mass, more preferably 5% by mass, and still more preferably 4.5% by mass. By setting the solid content concentration of the radiation-sensitive resin composition in the above range, the coating property of the radiation-sensitive resin composition is further improved, and as a result, the DOF performance in ISO-TAP pattern formation is further improved. .

<Method for Manufacturing Semiconductor Device>
The semiconductor element manufacturing method includes a step of forming a film on the surface of an inorganic substrate (hereinafter also referred to as “film forming step”), a step of exposing the film (hereinafter also referred to as “exposure step”), and the exposure. And a step of developing the film (hereinafter also referred to as “developing step”) and a step of ion-implanting the inorganic substrate using the developed film as a mask (hereinafter also referred to as “ion implantation step”). In the method of manufacturing the semiconductor element, the film is formed from the radiation-sensitive resin composition for ion implantation. Hereinafter, each step will be described.

[Film formation process]
In this step, a film is formed on the surface of the inorganic substrate. Examples of the material for the inorganic substrate include silicon, silicon oxide, silicon nitride, and silicon oxynitride. Moreover, what coat | covered these board | substrates with aluminum etc. can be used. Of these, silicon, silicon oxide, and silicon nitride are preferable.

  Examples of the coating method include spin coating (spin coating), cast coating, and roll coating. In addition, as a minimum of the average thickness of the resist film formed, 50 nm is preferable, 70 nm is more preferable, 90 nm is further more preferable, 100 nm is especially preferable. The upper limit of the average thickness is preferably 5,000 nm, more preferably 1,000 nm, still more preferably 500 nm, and particularly preferably 200 nm.

  After apply | coating the said radiation sensitive resin composition, you may volatilize the solvent in a coating film by prebaking (PB) as needed. The temperature of PB is appropriately selected depending on the composition of the radiation sensitive resin composition, but the lower limit of the temperature of PB is preferably 30 ° C, more preferably 50 ° C, and further preferably 80 ° C. As an upper limit of the said temperature, 200 degreeC is preferable, 170 degreeC is more preferable, and 150 degreeC is further more preferable. The lower limit of the PB time is preferably 5 seconds, and more preferably 10 seconds. The upper limit of the time is preferably 600 seconds, and more preferably 300 seconds.

  In order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film disclosed in, for example, Japanese Patent Laid-Open No. 5-188598 can be provided on the resist layer. Furthermore, in order to prevent the acid generator and the like from flowing out of the resist layer, a liquid immersion protective film disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-352384 can be provided on the resist layer. These techniques can be used in combination.

[Exposure process]
In this step, the resist film formed in the resist film forming step is exposed. This exposure is performed on a desired region through a mask for forming a specific pattern, preferably an ISO-TAP pattern. In this case, reduction projection exposure may be performed.

  The exposure can be performed by immersion exposure through immersion liquid. Examples of the immersion liquid include water and a fluorine-based inert liquid. The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient that is as small as possible so as to minimize distortion of the optical image projected onto the film. In the case of excimer laser light (wavelength 193 nm), it is preferable to use water from the viewpoints of availability and easy handling in addition to the above-described viewpoints. When water is used, an additive that decreases the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the resist layer on the wafer and can ignore the influence on the optical coating on the lower surface of the lens. The water used is preferably distilled water.

  As exposure light used for exposure, various electromagnetic waves or charged particle beams can be used, and [B] is appropriately selected according to the type of acid generator. Examples of electromagnetic waves include ultraviolet rays, far ultraviolet rays, Visible light, X-rays, γ-rays and the like can be mentioned, and examples of charged particle beams include electron beams and α-rays. Among these, electromagnetic waves are preferable, far infrared rays are more preferable, ArF excimer laser light and KrF excimer laser light (wavelength 248 nm) are further preferable, and ArF excimer laser light is further preferable. The exposure conditions such as the exposure amount are appropriately selected according to the blending composition of the radiation-sensitive resin composition, the type of additive, and the like.

  In addition, post exposure baking (PEB) is preferably performed after exposure. By performing PEB, the dissociation reaction of the acid dissociable group (I) and the acid dissociable group (II) in the [A] polymer component of the radiation-sensitive resin composition can smoothly proceed. As a minimum of the temperature of PEB, 30 ° C is preferred, 50 ° C is more preferred, and 80 ° C is still more preferred. As an upper limit of the said temperature, 200 degreeC is preferable, 170 degreeC is more preferable, and 130 degreeC is further more preferable. The lower limit of the PEB time is preferably 5 seconds, and more preferably 10 seconds. The upper limit of the time is preferably 600 seconds, and more preferably 300 seconds.

[Development process]
In this step, the exposed film is developed. Examples of the developer used for the development include an aqueous alkali solution (alkaline developer) and a solution containing an organic solvent (organic solvent developer). Thereby, a predetermined resist pattern is formed.

  Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine. , Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4.3. 0.0] -5-nonene, and an alkaline aqueous solution in which at least one of alkaline compounds is dissolved. In these, a TMAH aqueous solution is preferable and a 2.38 mass% TMAH aqueous solution is more preferable.

  Examples of the organic solvent developer include organic solvents such as hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, alcohol solvents, and liquids containing organic solvents. Examples of the organic solvent include one or more of the solvents exemplified as the [C] solvent of the above-described radiation-sensitive resin composition. Among these, ester solvents and ketone solvents are preferable. As the ester solvent, an acetate solvent is preferable, and n-butyl acetate is more preferable. As the ketone solvent, a chain ketone is preferable, and 2-heptanone is more preferable. The lower limit of the content of the organic solvent in the organic solvent developer is preferably 80% by mass, more preferably 90% by mass, further preferably 95% by mass, and particularly preferably 99% by mass. Examples of components other than the organic solvent in the organic solvent developer include water and silicone oil.

  These developers may be used alone or in combination of two or more. In general, after development, the substrate is washed with water or the like and dried.

  The developer is preferably an alkali developer, more preferably a TMAH aqueous solution, and even more preferably a 2.38 mass% TMAH aqueous solution.

  As a developing method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle method) ), A method of spraying the developer on the substrate surface (spray method), a method of continuously applying the developer while scanning the developer coating nozzle on the substrate rotating at a constant speed (dynamic dispensing method) Etc.

[Ion implantation process]
In this step, ions are implanted into the inorganic substrate using the developed film (resist pattern) as a mask. This ion implantation can be performed by a known method using a known ion implantation apparatus.

  An ion-implanted substrate can be obtained by the above-described steps. According to the method for manufacturing a semiconductor element, an excellent resist pattern can be formed by using a radiation-sensitive resin composition having excellent DOF performance for ISO-TAP pattern formation. By using the mask, an inorganic substrate in which ions are implanted in a desired region can be obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The measuring method of various physical property values is shown below.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]
Using Tosoh GPC columns (G2000HXL: 2, G3000HXL: 1, G4000HXL: 1), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, sample concentration: 1.0 mass%, sample injection amount: 100 μL Column temperature: 40 ° C., detector: measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under the analysis conditions of a differential refractometer. The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.

[ ¹³ C-NMR analysis]
JNM-ECX400 manufactured by JEOL Ltd. was used and deuterated chloroform was used as a measurement solvent, and an analysis for determining the content ratio (mol%) of each structural unit in each polymer was performed.

<[A] Synthesis of polymer component>
[[A1] Synthesis of polymer]
[A1] Monomers used for polymer synthesis are shown below.

[Synthesis Example 1] (Synthesis of Polymer (A1-1))
9.47 g (50 mol%) of the compound (M-1) and 10.30 g (50 mol%) of the compound (M-15) are dissolved in 40 g of 2-butanone, and 0.79 g of AIBN as a radical polymerization initiator (total A monomer solution was prepared by adding 5 mol%) to the monomer. Next, a 100 mL three-necked flask containing 20 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was cooled with water and cooled to 30 ° C. or lower. The cooled polymerization reaction liquid was put into 400 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 80 g of methanol, filtered, and dried at 50 ° C. for 17 hours to synthesize a white powdery polymer (A1-1) (15.8 g, yield 80). %). Mw of the polymer (A1-1) was 7,400, and Mw / Mn was 1.53. As a result of ¹³ C-NMR analysis, the content ratios of structural units derived from (M-1) and (M-15) were 50.1 mol% and 49.9 mol%.

[Synthesis Examples 2 to 54] (Synthesis of Polymers (A1-2) to (A1-54))
Polymers (A1-2) to (A1-54) were synthesized by performing the same operations as in Synthesis Example 1 except that the types and amounts of monomers shown in Table 1 were used.

[[A2] Synthesis of polymer]
[A2] Monomers used for polymer synthesis are shown below.

[Synthesis Example 55] (Synthesis of Polymer (A2-1))
Monomer prepared by dissolving 60 mol% of the above compound (M-A), 25 mol% of the compound (MG), 15 mol% of the compound (MH) and AIBN as a radical polymerization initiator in 50 g of 2-butanone. A solution was prepared. The total amount of charged monomers was 50 g. In addition, mol% of each monomer represents mol% with respect to the whole monomer amount, and the usage-amount of the radical polymerization initiator was 5 mol% with respect to the sum total of a monomer and a radical polymerization initiator. Next, 50 g of 2-butanone was added to a 500 mL three-necked flask equipped with a thermometer and a dropping funnel, and a nitrogen purge was performed for 30 minutes. Then, it heated so that it might become 80 degreeC, stirring the inside of a flask with a magnetic stirrer. Next, the monomer solution was dropped into the flask over 3 hours using a dropping funnel. After dropping, the mixture was aged for 3 hours, and then cooled to 30 ° C. or lower to obtain a polymerization reaction solution. Then, after transferring the polymerization reaction liquid to a 2 L separatory funnel, the polymerization reaction liquid was uniformly diluted with 150 g of n-hexane, and 600 g of methanol was added and mixed. Next, 30 g of distilled water was added, and the mixture was stirred and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to obtain a propylene glycol monomethyl ether solution of the polymer (A2-1). This polymer (A2-1) had Mw of 6,000 and Mw / Mn of 1.7. As a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (MA), (MG) and (MH) was 58.8 mol%, 23.4 mol% and It was 17.8 mol%.

[Synthesis Examples 56 to 67] (Synthesis of Polymers (A2-2) to (A2-13))
In Synthesis Example 55, polymers (A2-2) to (A2-13) were synthesized in the same manner as in Synthesis Example 55 except that the types and amounts of monomers shown in Table 3 below were used. About each obtained polymer, the measured value of the content rate of the structural unit derived from each monomer, a weight average molecular weight (Mw), and dispersion degree (Mw / Mn) is shown according to Table 3.

<Preparation of radiation-sensitive resin composition>
The [B] acid generator, [C] solvent and [D] acid diffusion controller used for the preparation of the radiation sensitive resin composition are shown below.

[[B] acid generator]
Each structural formula is shown below.
B-1: 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-butanesulfonate B-2: triphenylsulfonium 2- (adamantan-1-yl) -1,1-difluoroethane-1-sulfonate B-3: triphenylsulfonium 2- (adamantan-1-ylcarbonyloxy) -1,1,3,3,3-pentafluoropropane-1-sulfonate B-4: triphenylsulfonium adamantane-1-yloxycarbonyldifluoromethanesulfonate B-5: 4-(((Adamantane-1-yloxy) methoxy) -3,5-dimethylphenyl) diphenylsulfonium norbornane sultone-2-yloxycarbonyldifluoromethanesulfonate B-6: Triphenylsulfonium 4,4,5 , 6,6-hexafluoro-1,3,2-dithiazinane-2-id-1,1,3,3-tetraoxide B-7: 1- (butoxynaphthalen-1-yl) tetrahydro-1H-thiophene- 1-ium 4- (adamantane-1-carbonyloxy) -1,1,2-trifluorobutanesulfonate

[[C] solvent]
C-1: Propylene glycol monomethyl ether acetate C-2: Cyclohexanone C-3: γ-butyrolactone

[[D] acid diffusion controller]
Each structural formula is shown below.
D-1: Triphenylsulfonium salicylate D-2: Triphenylsulfonium 10-camphorsulfonate D-3: N- (n-undecan-1-ylcarbonyloxyethyl) morpholine D-4: 2,6-dii -Propylaniline D-5: Tri-n-pentylamine D-6: 2-phenylbenzimidazole D-7: tert-pentyl-4-hydroxypiperidine-1-carboxylate

[Preparation of radiation-sensitive resin composition for dry exposure]
[Example 1]
[A] 100 parts by mass of (A1-31) as a polymer component, [B] 8.5 parts by mass of (B-1) as an acid generator, [C] 1,800 as a solvent (C-1) A membrane having a pore size of 0.2 μm, blended with mass parts, (C-2) 770 parts by mass and (C-3) 30 parts by mass, and [D] 3.5 parts by mass of (D-1) as an acid diffusion controller. A radiation sensitive resin composition for dry exposure (J-1) was prepared by filtering with a filter.

[Examples 2 to 24 and Comparative Examples 1 to 30]
Except having used each component of the kind and content shown in following Table 2, it operated similarly to Example 1 and prepared each radiation sensitive resin composition (J-2)-(J-54) for dry exposure. did.

<Formation of resist pattern>
As the substrate, a silicon wafer was used in which a film having an average thickness of 77 nm was formed on the wafer surface using “ARC29” of Nissan Chemical Industries. The prepared radiation-sensitive resin composition was applied onto a substrate by spin coating using “Clean Track ACT8” manufactured by Tokyo Electron, and subjected to PB on a hot plate at 120 ° C. for 60 seconds to obtain an average thickness of 120 nm. The resist film was formed. The formed resist film was exposed through a mask pattern using an ArF excimer laser exposure apparatus (Nikon Corporation “S306C”, numerical aperture 0.78). Next, PEB was performed at 105 ° C. for 60 seconds, and then developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 4 seconds, washed with water, and dried to form a positive resist pattern. . At this time, the exposure amount at which the ISO-TAP pattern with a diameter of 110 nm in the mask becomes a size with a diameter of 110 nm in the resist pattern was determined as the optimum exposure amount.

<Evaluation>
The DOF performance was evaluated according to the following method. The evaluation results are shown in Table 5 below.
[DOF performance]
Using a scanning electron microscope ("S-9380" from Hitachi High-Technologies Corporation), the depth of focus performance (DOF performance) was evaluated in an ISO-TAP pattern with a diameter of 110 nm formed at the optimum exposure dose. The depth of focus (nm) at which the diameter was 110 nm ± 10% was measured, and this was taken as DOF performance. The DOF performance was “good” when the thickness was 100 nm or more, and “bad” when the thickness was less than 100 nm.

[Preparation of radiation-sensitive resin composition for immersion exposure]
[Example 25]
[A] 100 parts by mass of (A1-31) as a polymer component, 3.0 parts by mass of (A2-1) as a [A2] polymer, [B] (B-1) as an acid generator 5 parts by mass, (C-1) 1,800 parts by mass as [C] solvent, (C-2) 770 parts by mass and (C-3) 30 parts by mass and [D] (D -1) A radiation-sensitive resin composition for immersion exposure (K-1) was prepared by blending 3.5 parts by mass and filtering through a membrane filter having a pore size of 0.2 μm.

[Examples 26 to 48 and Comparative Examples 31 to 60]
Except having used each component of the kind and compounding quantity which are shown in following Table 6, it operated similarly to Example 25 and carried out the radiation sensitive resin composition (K-2)-(K-54) for immersion exposure. Prepared.

<Formation of resist pattern>
As the substrate, a silicon wafer having an average thickness of 105 nm formed using “ARC66” of Nissan Chemical Industries, Ltd. on the wafer surface was used. The prepared radiation sensitive resin composition for immersion exposure is applied on a substrate by spin coating using “Clean Track ACT12” of Tokyo Electron, and PB is performed on a hot plate at 120 ° C. for 60 seconds. Thus, a resist film having an average thickness of 120 nm was formed. The formed resist film was exposed through a mask pattern using an ArF excimer laser exposure apparatus (Nikon “XT1900i”, numerical aperture 1.35). Next, PEB is performed at 105 ° C. for 60 seconds, and then developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 40 seconds, washed with water, and dried to form a positive resist pattern. did. At this time, the exposure amount at which the ISO-TAP pattern with a diameter of 90 nm in the mask becomes a size with a diameter of 90 nm in the resist pattern was determined as the optimum exposure amount.

<Evaluation>
The DOF performance was evaluated according to the following method. The evaluation results are shown in Table 7 below.
[DOF performance]
Using an scanning electron microscope (“CG-5000” from Hitachi High-Technologies Corporation), an ISO-TAP pattern with a diameter of 90 nm formed at an optimum exposure dose, the depth of focus at which the pattern diameter is 90 nm ± 10% (Nm) was measured and this was designated as DOF performance. The DOF performance was “good” when the thickness was 100 nm or more, and “bad” when the thickness was less than 100 nm.

  As is clear from the results of Tables 5 and 7, the radiation-sensitive resin compositions of the examples had good ISO-TAP pattern DOF performance in both dry exposure and immersion exposure. On the other hand, the radiation-sensitive resin composition of the comparative example was defective.

According to the radiation sensitive resin composition for ion implantation of the present invention and the method for manufacturing a semiconductor device, an ISO-TAP pattern can be formed by exhibiting excellent DOF performance, and such an excellent pattern is masked. By doing so, a semiconductor element including an inorganic substrate in which ions are implanted in a desired region can be manufactured. Accordingly, these can be suitably used for the manufacture of semiconductor products and the like, and the performance, reliability, yield, etc. of the products can be improved.

Claims (10)

In the same or different polymers, a first structural unit containing a first acid-dissociable group having a bridge-like bond and a second structural unit containing a second acid-dissociable group other than the first acid-dissociable group A polymer component having,
Containing a radiation-sensitive acid generator and a solvent,
The content ratio of the first structural unit to the total of the first structural unit and the second structural unit in the polymer component is 5 mol% or more and 80 mol% or less,
The radiation sensitive resin composition for ion implantation whose total content of components other than the said solvent is 2 mass% or more and 6 mass% or less.   The radiation sensitive resin composition for ion implantation according to claim 1, wherein the polymer component includes a polymer having the first structural unit and the second structural unit.   The radiation sensitive resin composition for ion implantation according to claim 1, wherein the polymer component is a mixture containing a polymer having the first structural unit and a polymer having the second structural unit. The first acid dissociable group is a group represented by the following formula (1-1), a group represented by the following formula (1-2), or a combination thereof. The radiation sensitive resin composition for ion implantation as described in 2.

(In Formula (1-1), R ¹ is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ² and R ³ are each independently a trivalent chain having 1 to 20 carbon atoms. Or a trivalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and R ⁴ is a substituted or unsubstituted divalent chain hydrocarbon group having 1 or 2 carbon atoms. ¹ represents a binding site to a moiety other than the group represented by the formula (1-1) in the first structural unit.
In formula (1-2), R ⁵ and R ⁶ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ⁷ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ⁸ and R ⁹ are each independently a trivalent chain hydrocarbon group having 1 to 20 carbon atoms or a trivalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. R ¹⁰ is a substituted or unsubstituted divalent chain hydrocarbon group having 1 or 2 carbon atoms. R ⁷ and R ⁸ may be combined with each other to form an alicyclic structure having 5 to 20 ring members together with the carbon atom to which R ⁷ is bonded, R ⁸ , R ⁹ and R ¹⁰ . * ² represents a binding site to a moiety other than the group represented by the formula (1-2) in the first structural unit. ) The radiation sensitive resin composition for ion implantation according to any one of claims 1 to 4, wherein the second acid dissociable group is represented by the following formula (2).

(In formula (2), R ¹¹ is a monovalent chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent monocyclic alicyclic hydrocarbon group having 3 to 20 carbon atoms. R ¹² and R ¹³ is each independently a monovalent chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent monocyclic alicyclic hydrocarbon group having 3 to 10 carbon atoms, or these groups. Represents a monocyclic alicyclic structure having 3 to 10 ring members composed of carbon atoms to which these are bonded to each other, and * ³ is other than the group represented by the formula (2) in the second structural unit The binding site to the part of is shown.)   The radiation sensitive resin composition for ion implantation according to any one of claims 1 to 5, wherein the first acid dissociable group includes a norbornane ring, an adamantane ring, a tricyclodecane ring or a tetracyclododecane ring. object.   The total content of the first structural unit and the second structural unit with respect to all the structural units constituting the polymer component is 30 mol% or more and 70 mol% or less, according to any one of claims 1 to 6. The radiation sensitive resin composition for ion implantation as described. The ion according to any one of claims 1 to 7, wherein the first structural unit is represented by the following formula (3-1), and the second structural unit is represented by the following formula (3-2). Radiation sensitive resin composition for implantation.

(In Formula (3-1), R ¹⁴ represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z ¹ represents the first acid dissociable group.
In formula (3-2), R ¹⁵ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Z ² is the second acid dissociable group. )   The radiation sensitivity for ion implantation according to any one of claims 1 to 8, wherein the polymer component further has a third structural unit including a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof. Resin composition. Forming a film on the surface of the inorganic substrate;
Exposing the film,
A step of developing the exposed film, and a step of ion-implanting the inorganic substrate using the developed film as a mask,
The manufacturing method of the semiconductor element which forms the said film | membrane with the radiation sensitive resin composition for ion implantation of any one of Claims 1-9.