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JP-7855421-B2 - Salt, acid generator, resist composition, and method for producing resist patterns

JP7855421B2JP 7855421 B2JP7855421 B2JP 7855421B2JP-7855421-B2

Inventors

  • 小室 勝洋
  • 市川 幸司

Assignees

  • 住友化学株式会社

Dates

Publication Date
20260508
Application Date
20220621
Priority Date
20210622

Claims (11)

  1. An acid generator containing a salt represented by formula (I). [In formula (I), Q1 and Q2 each independently represent a hydrogen atom, a fluorine atom, a C1-C6 alkyl group, or a C1-C6 perfluoroalkyl group. R11 and R12 each independently represent a hydrogen atom, a fluorine atom, a C1-C6 alkyl group, or a C1-C6 perfluoroalkyl group. z represents an integer from 0 to 6, and when z is 2 or greater, multiple R11 and R12 may be the same or different from each other. X1 represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, where * represents a binding site with C( R11 )( R12 ) or C( Q1 )( Q2 ). L1 represents a hydrocarbon group having 1 to 40 carbon atoms, which may have a single bond or substituents, and the -CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -SO2-, or -CO- . R1 represents an iodine atom . R2 represents a halogen atom, a hydroxyl group, a C1-C12 haloalkyl group, or a C1-C12 alkyl group, and the -CH2- contained in the haloalkyl group and the alkyl group may be replaced with -O- or -CO-. m² represents an integer from 1 to 6, and when m² is 2 or greater, multiple R² values may be the same or different from each other. At least one R2 represents a hydroxyl group, an alkoxy group having 1 to 5 carbon atoms, or an alkoxyalkoxy group having 2 to 4 carbon atoms. Z + represents an organic cation.
  2. L1 is a single bond, * -L2- or * -L2 - X3- L3- ( L2 represents a chain hydrocarbon group having 1 to 10 carbon atoms which may have substituents, a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have substituents, or a group formed by a combination of a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have substituents and a chain hydrocarbon group having 1 to 8 carbon atoms which may have substituents, and the -CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2- , and the -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-. * represents the bonding site with X1 . X3 represents **-CO-O-, **-O-CO-, **-O-CO-O- or **-O-, and ** represents the bonding site with L2 . The acid generator according to claim 1, wherein 3 represents a chain hydrocarbon group having 1 to 8 carbon atoms, which may have single bonds or substituents, and the -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-.
  3. The acid generator according to claim 1, wherein R2 is an iodine atom, a fluorine atom, a hydroxyl group, a C1-C6 haloalkyl group, or a C1-C6 alkyl group (the -CH2- contained in the haloalkyl group and the alkyl group may be replaced with -O- or -CO-).
  4. A resist composition containing an acid generator according to any one of claims 1 to 3 and a resin having an acid-unstable group.
  5. The resist composition according to claim 4, wherein the resin having an acid-unstable group comprises at least one selected from the group consisting of a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), and a structural unit represented by formula (a1-2) . [In formulas (a1-0), (a1-1), and (a1-2), L a01 , L a1 , and L a2 each independently represent -O- or *-O-(CH 2 ) k1 -CO-O-, where k1 is an integer from 1 to 7, and * represents the bond site with -CO-. Ra01 , Ra4 , and Ra5 each independently represent a hydrogen atom, a halogen atom, or a C1-C6 alkyl group which may contain a halogen atom. R a02 , R a03 , and R a04 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. Ra6 and Ra7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by a combination of these. m1 represents an integer between 0 and 14. n1 represents an integer between 0 and 10. n1' represents an integer between 0 and 3.
  6. The resist composition according to claim 4 , wherein the resin having an acid-unstable group comprises a structural unit represented by formula (a2-A). [In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms that may contain a halogen atom. R a51 represents a halogen atom, a hydroxyl group, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C2-C12 alkoxyalkyl group, a C2-C12 alkoxyalkoxy group, a C2-C4 alkylcarbonyl group, a C2-C4 alkylcarbonyloxy group, an acryloyloxy group, or a methacryloyloxy group. A a50 represents a single bond or *-X a51- (A a52 -X a52 ) nb- , where * represents the bonding site with the carbon atom to which -R a50 is bonded. A a52 represents an alkanediyl group with 1 to 6 carbon atoms. X a51 and X a52 independently represent -O-, -CO-O-, or -O-CO-, respectively. nb represents either 0 or 1. mb represents an integer between 0 and 4. If mb is an integer greater than or equal to 2, multiple R a51s may be identical or different from each other.
  7. The resist composition according to claim 4 , further comprising a salt that generates an acid with a lower acidity than the acid generated from the acid generator.
  8. (1) A step of applying the resist composition according to claim 4 onto a substrate, (2) A step of drying the coated composition to form a composition layer, (3) Exposure step of the composition layer, (4) A step of heating the composition layer after exposure, and (5) A step of developing the composition layer after heating. A method for manufacturing a resist pattern that includes [the specified element].
  9. A salt represented by formula (I). [In formula (I), Q1 and Q2 each independently represent a hydrogen atom, a fluorine atom, a C1-C6 alkyl group, or a C1-C6 perfluoroalkyl group. R11 and R12 each independently represent a hydrogen atom, a fluorine atom, a C1-C6 alkyl group, or a C1-C6 perfluoroalkyl group. z represents an integer from 0 to 6, and when z is 2 or greater, multiple R11 and R12 may be the same or different from each other. X1 represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, where * represents a binding site with C( R11 )( R12 ) or C( Q1 )( Q2 ). L1 represents a hydrocarbon group having 1 to 40 carbon atoms, which may have a single bond or substituents, and the -CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -SO2-, or -CO- . R1 represents an iodine atom . R2 represents a halogen atom, a hydroxyl group, a C1-C12 haloalkyl group, or a C1-C12 alkyl group, and the -CH2- contained in the haloalkyl group and the alkyl group may be replaced with -O- or -CO-. m² represents an integer from 1 to 6, and when m² is 2 or greater, multiple R² values may be the same or different from each other. At least one R2 represents a hydroxyl group, an alkoxy group having 1 to 5 carbon atoms, or an alkoxyalkoxy group having 2 to 4 carbon atoms. Z + represents an organic cation.
  10. L1 is a single bond, * -L2- or * -L2 - X3- L3- ( L2 represents a chain hydrocarbon group having 1 to 10 carbon atoms which may have substituents, a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have substituents, or a group formed by a combination of a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have substituents and a chain hydrocarbon group having 1 to 8 carbon atoms which may have substituents, and the -CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2- , and the -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-. * represents the bonding site with X1 . X3 represents **-CO-O-, **-O-CO-, **-O-CO-O- or **-O-, and ** represents the bonding site with L2 . The salt according to claim 9, wherein 3 represents a chain hydrocarbon group having 1 to 8 carbon atoms, which may have single bonds or substituents, and the -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-.
  11. The salt according to claim 9 or 10, wherein R2 is an iodine atom, a fluorine atom, a hydroxyl group, a C1-C6 haloalkyl group, or a C1-C6 alkyl group (the -CH2- contained in the haloalkyl group and the alkyl group may be replaced with -O- or -CO-).

Description

This invention relates to salts, acid generators, resist compositions, and methods for producing resist patterns. Patent Document 1 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. Patent Document 2 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. Patent Document 3 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. Japanese Patent Publication No. 2018-005224Japanese Patent Publication No. 2018-025789Japanese Patent Publication No. 2020-173437 In this specification, "(meth)acrylic monomer" means "at least one of acrylic monomers and methacrylic monomers." The notations "(meth)acrylate" and "(meth)acrylic acid" have the same meaning. For groups described herein that can take both linear and branched structures, either is acceptable. When the -CH2- contained in hydrocarbon groups, etc., is replaced by -O-, -S-, -CO- or -SO2- , the same example shall apply to each group. "Combined group" means a group formed by bonding two or more of the exemplified groups, and the valencies of these groups may be appropriately changed depending on the bonding configuration. "Derived from" or "induced from" means that the polymerizable C=C bond contained in the molecule becomes a -C-C- group (single bond) through polymerization. If stereoisomers exist, all stereoisomers are included. In this specification, "solid content of the resist composition" means the total amount of the resist composition excluding the solvent (E) described later. [Salt represented by formula (I)] This invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)"). In salts (I), the side with a negative charge is sometimes called an "anion (I)," and the side with a positive charge is sometimes called a "cation (I)." [In the formula, all signs have the same meaning as described above.] In formula (I), examples of perfluoroalkyl groups for Q1 , Q2 , R11 , and R12 include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluorosec-butyl, perfluorotert-butyl, perfluoropentyl, and perfluorohexyl groups. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 4, and more preferably 1 to 3. Examples of alkyl groups for Q1 , Q2 , R11 , and R12 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups. The number of carbon atoms in the alkyl group is preferably 1 to 4, and more preferably 1 to 3. Q1 and Q2 preferably contain at least one fluorine atom or perfluoroalkyl group, more preferably at least one is a fluorine atom or a perfluoroalkyl group, more preferably each independently be a trifluoromethyl group or a fluorine atom, and even more preferably both be fluorine atoms. R11 and R12 are each independently preferably a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and more preferably a hydrogen atom or a trifluoromethyl group. z is preferably an integer from 0 to 4, more preferably an integer from 0 to 3, and even more preferably 0 or 1. X1 is preferably *-CO-O-, *-O-CO-O-, or *-O-CO-, and more preferably *-CO-O- or *-O-CO- (where * represents a bonding site with C( R11 )( R12 ) or C( Q1 )( Q2 )). Examples of hydrocarbon groups in L1 include divalent chain hydrocarbon groups such as alkanediyl groups, monocyclic or polycyclic (including spiro ring) divalent alicyclic hydrocarbon groups, and divalent aromatic hydrocarbon groups. Groups formed by combining two or more of these groups (for example, a divalent hydrocarbon group formed from an alicyclic hydrocarbon group or aromatic hydrocarbon group and a chain hydrocarbon group) are also possible. The number of carbon atoms in the hydrocarbon group is preferably 1 to 38, more preferably 1 to 36, even more preferably 1 to 32, and even more preferably 1 to 28. Examples of alkanediyl groups include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group, and Examples of branched alkanediyl groups include ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group. The number of carbon atoms in the chain-like hydrocarbon group is preferably 1 to 18, more preferably 1 to 12, even more preferably 1 to 10, even more preferably 1 to 8, even more preferably 1 to 7, even more prefe