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CN-122010808-A - Onium salt type monomer, polymer, chemically amplified resist composition, and pattern forming method

CN122010808ACN 122010808 ACN122010808 ACN 122010808ACN-122010808-A

Abstract

The present invention relates to onium salt type monomers, polymers, chemically amplified resist compositions and pattern forming methods. The object of the present invention is to provide a sulfonium salt type monomer used in a chemically amplified resist composition excellent in solvent solubility, high sensitivity, high contrast, and excellent in lithographic performance such as LWR, CDU, EL, DOF in optical lithography using high-energy rays, a polymer containing a repeating unit derived from the sulfonium salt type monomer, a chemically amplified resist composition containing the polymer, and a pattern forming method using the chemically amplified resist composition. The solution of the present invention is an onium salt type monomer represented by the following formula (A).

Inventors

  • Fukushima will be big

Assignees

  • 信越化学工业株式会社

Dates

Publication Date
20260512
Application Date
20251110
Priority Date
20241111

Claims (16)

  1. 1. An onium salt type monomer represented by the following formula (A); wherein n1 is 0,1, 2,3 or 4, n2 is 0 or 1, n3 is 0,1, 2,3 or 4, n4 is 0,1, 2,3 or 4, but n2 is 0≤n3+n4≤4, n2 is 1≤n3+n4≤6; r A is each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 1 is a halogen atom, a hydroxyl group, a nitro group, a cyano group, a hydrocarbon group of 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group of 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylthio group of 1 to 20 carbon atoms which may contain a heteroatom, and when n1 is 2, 3 or 4, each R 1 may be the same or different from each other, and plural R 1 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded; R 2 is a halogen atom other than fluorine atom, nitro group, hydroxyl group, hydrocarbon group of 1 to 20 carbon atoms or hydrocarbon group of 1 to 20 carbon atoms, the hydrocarbon group, hydrocarbon group and hydrocarbon group may contain hetero atom other than fluorine atom, when n4 is 2,3 or 4, R 2 may be the same or different from each other, and plural R 2 may be bonded to each other to form a ring together with the carbon atom to which they are bonded; R F is a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms, and when n3 is 2, 3 or 4, R F may be the same or different from each other; Each of L A and L B is independently a single bond, an ether bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonamide bond, a carbonate ester bond, or a urethane bond; x L1 is a single bond or a C1-40 alkylene group which may contain a hetero atom; Z + is an onium cation.
  2. 2. The onium salt type monomer according to claim 1, represented by the following formula (A1); Wherein n1, n3, n4, R A 、R 1 、R 2 、R F 、L A 、L B 、X L1 and Z + are the same as those described above.
  3. 3. The onium salt type monomer according to claim 2, represented by the following formula (A2); Wherein n1, R A 、R 1 、L A 、L B 、X L1 and Z + are the same as those described above.
  4. 4. The onium salt type monomer according to claim 1, wherein Z + is a sulfonium cation represented by the following formula (Z-1) or an iodonium cation represented by the following formula (Z-2); Wherein R ct1 ～R ct5 is a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom, and R ct1 and R ct2 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
  5. 5. The onium salt type monomer according to claim 1, wherein Z + is a sulfonium cation represented by the following formula (Z-3); Wherein m1 is 0 or 1, m2 is 0 or 1, m3 is 0 or 1, m4 is 0, 1,2,3 or 4, m5 is 0, 1,2,3 or 4, m6 is 0, 1,2,3, 4, 5 or 6, m7 is 0, 1,2,3, 4, 5 or 6, m8 is 0, 1 or 2, m9 is 0, 1 or 2, m10 is 0, 1 or 2, m11 is 0 or 1, m12 is 0, 1,2,3 or 4, m13 is 0, 1 or 2, m14 is 0, 1 or 2; but m1 is 0≤m6+m9≤4, m1 is 0≤m6+m9≤6, m2 is 0≤m7+m10≤4, m2 is 0≤m7+m10≤6, m3 is 0≤1; m4+m5+m8+m14 is not less than 4, m3 is not less than 1 and not more than 1+m4+m5+m8+m14 is not less than 6, m11 is not less than 0 and not more than 12+m13 is not less than 4, and m11 is not less than 0 and not more than 12+m13 is not less than 6; in addition, m4+m12 is more than or equal to 1; R F1 ～R F3 is independently a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms or a fluorinated saturated hydrocarbon sulfur group having 1 to 6 carbon atoms, R F1 may be the same or different from each other when m5 is 2, 3 or 4, R F2 may be the same or different from each other when m6 is 2, 3, 4, 5 or 6, and R F3 may be the same or different from each other when m7 is 2, 3, 4, 5 or 6; R ct6 ～R ct9 is a halogen atom other than an iodine atom and a fluorine atom, a nitro group, a cyano group, a hydrocarbon group of 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarbyloxy group of 1 to 20 carbon atoms which may contain a hetero atom or a hydrocarbylthio group of 1 to 20 carbon atoms which may contain a hetero atom, m8 is 2, 2R ct6 may be the same or different from each other, 2R ct6 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, m9 is 2, 2R ct7 may be the same or different from each other, 2R ct7 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, m10 is 2, 2R ct8 may be the same or different from each other, 2R ct8 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and m13 is 2, 2R ct9 may be the same or different from each other to form a ring together with the carbon atom to which they are bonded; the aromatic rings of S + directly bonded to each other in the sulfonium cation may be bonded to each other to form a ring together with S + ; each of L C and L D is independently a single bond, an ether bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonamide bond, a carbonate ester bond, or a urethane bond; X L2 is a single bond or a C1-40 alkylene group which may contain a hetero atom.
  6. 6. A polymer comprising repeat units from the onium salt type monomer according to any one of claims 1 to 4.
  7. 7. The polymer according to claim 6, which functions as a polymer-bonded acid generator.
  8. 8. The polymer according to claim 6, further comprising at least 1 selected from the group consisting of a repeating unit represented by the following formula (a 1), a repeating unit represented by the following formula (a 2), and a repeating unit represented by the following formula (a 3); wherein R A is each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; X 1 is a single bond, phenylene, naphthylene, -C (=O) -O-X 11 -, or-C (=O) -NH-X 11 -, wherein the phenylene or naphthylene may be substituted with hydroxyl, nitro, cyano, saturated hydrocarbon group of 1 to 10 carbon atoms which may contain fluorine atom or halogen atom, X 11 is saturated hydrocarbon group of 1 to 10 carbon atoms, phenylene or naphthylene, and the saturated hydrocarbon group may contain hydroxyl, ether bond, ester bond or lactone ring; X 2 is a single bond, -C (=o) -O-, or, -C (=o) -NH-; * An atomic bond to a carbon atom of the main chain; R 11 is a halogen atom, cyano group, hydroxyl group, nitro group, hydrocarbon group of 1 to 20 carbon atoms which may contain a heteroatom, hydrocarbyloxy group of 2 to 20 carbon atoms which may contain a heteroatom, R 11 may be the same or different from each other when a1 is 2,3 or 4; AL 1 and AL 2 are each independently an acid labile group; a1 is 0,1, 2, 3 or 4; wherein a11 is 0 or 1, a12 is 0,1, 2 or 3 when a11 is 0, and 0,1, 2, 3, 4 or 5 when a11 is 1; R A is hydrogen atom, fluorine atom, methyl or trifluoromethyl; X 3 is a single bond, -C (=o) -O-, or, -C (=o) -NH-; represents an atomic bond to a carbon atom of the main chain; X 4 is a single bond, an aliphatic alkylene group having 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a group obtained by combining them; X 5 and X 6 are each independently an oxygen atom or a sulfur atom, but X 4 and X 6 are bonded to adjacent carbon atoms of an aromatic ring; r 12 and R 13 are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, or R 12 and R 13 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded; R 14 is a halogen atom, a hydroxyl group, a cyano group, a nitro group, a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarbyloxy group having 2 to 20 carbon atoms which may contain a hetero atom, a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a hetero atom or-N (R 14A )(R 14B );R 14A and R 14B are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; when a12 is 2 or more, R 14 may be the same or different from each other, and a plurality of R 14 may be bonded to each other to form a ring together with the carbon atom of the aromatic ring to which they are bonded.
  9. 9. The polymer according to claim 6, further comprising at least 1 selected from the group consisting of a repeating unit represented by the following formula (b 1) and a repeating unit represented by the following formula (b 2); wherein R A is each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; Y 1 is a single bond or-C (=o) -O-, representing an atomic bond to a carbon atom of the backbone; R 21 is a hydrogen atom or a group having 1 to 20 carbon atoms and containing at least 1 structure selected from the group consisting of a hydroxyl group other than a phenolic hydroxyl group, a cyano group, a carbonyl group, a carboxyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, and a carboxylic anhydride (-C (=O) -O-C (=O) -); R 22 is a halogen atom, a carboxyl group, a nitro group, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 2 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbyloxy group having 2 to 20 carbon atoms which may contain a heteroatom, and b2 is 2,3 or 4, R 22 may be the same or different from each other; b1 is 1, 2, 3 or 4, b2 is 0,1, 2, 3 or 4, but 1≤b1+b2≤5.
  10. 10. A chemically amplified resist composition comprising (a) a base polymer comprising the polymer according to claim 6.
  11. 11. The chemically amplified resist composition according to claim 10, further comprising (B) an organic solvent.
  12. 12. The chemically amplified resist composition according to claim 10, further comprising (C) a quencher.
  13. 13. The chemically amplified resist composition according to claim 10, further comprising (D) a photoacid generator.
  14. 14. The chemically amplified resist composition according to claim 10, further comprising (E) a surfactant.
  15. 15. A pattern forming method comprising the steps of: forming a resist film on a substrate using the chemically amplified resist composition according to claim 10; Exposing the resist film to high-energy rays, and The exposed resist film is developed using a developer.
  16. 16. The pattern forming method according to claim 15, wherein the high-energy ray is a KrF excimer laser, an ArF excimer laser, an electron beam, or an extreme ultraviolet ray having a wavelength of 3 to 15 nm.

Description

Onium salt type monomer, polymer, chemically amplified resist composition, and pattern forming method Technical Field The invention relates to onium salt type monomer, polymer, chemical amplification resist composition and pattern forming method. Background Along with the high integration and high speed of LSI, the miniaturization of pattern rules is rapidly advanced. In particular, expansion of the flash memory market and increase in memory capacity have led to miniaturization. In the first miniaturization technology, mass production of 65nm node devices by ArF lithography is underway, and mass production preparation of 45nm node devices by ArF immersion lithography of the next generation is underway. In the next generation of 32nm node devices, immersion lithography, extreme Ultraviolet (EUV) lithography having a wavelength of 13.5nm, double exposure (double patterning lithography) of ArF lithography, and the like using an ultra-high NA lens formed by combining a liquid having a higher refractive index than water, a high refractive index lens, and a high refractive index resist film are candidates. As miniaturization progresses and the diffraction limit of light approaches, the contrast of light decreases. Because of the decrease in contrast of light, a decrease in hole pattern, resolution of a trench pattern, and focus margin (focus margin) occurs in the positive resist film. As patterns are miniaturized, roughness (LWR) of line width of line patterns and size uniformity (CDU) of hole patterns are regarded as problems. Some refer to the effects of the base polymer, the uneven distribution of the acid generator, agglomeration, and acid diffusion. Then, the LWR tends to be increased due to the thinning of the resist film, and the degradation of the LWR caused by the thinning accompanied by the progress of the thinning becomes a serious problem. In a resist composition for EUV lithography, it is necessary to achieve high sensitivity, high resolution and low LWR at the same time. When the acid diffusion distance is shortened, LWR becomes smaller but sensitivity becomes lower. For example, by lowering the Post Exposure Bake (PEB) temperature, LWR becomes smaller, but sensitivity becomes lower. Increasing the amount of quencher added also reduces LWR, but reduces sensitivity. The trade-off relationship of sensitivity to LWR must be broken. In order to suppress the acid diffusion, a resist compound containing a repeating unit derived from an onium salt of a sulfonic acid having a polymerizable unsaturated bond has been proposed (patent document 1). Such a so-called polymer-bonded acid generator is characterized by extremely short acid diffusion because it generates a polymer-type sulfonic acid by exposure to light. Further, by increasing the ratio of the acid generator, the sensitivity can be improved. In the case of the additive type acid generator, the sensitivity is also increased when the amount of the additive is increased, but the acid diffusion distance is also increased at this time. Since the acid is unevenly diffused, LWR and CDU are deteriorated if the acid diffusion is increased. In the balance of sensitivity, LWR and CDU, it can be said that the polymeric acid generator has a higher capacity. Since the absorption of the EUV at a wavelength of 13.5nm by the iodine atoms is very large, the effect of secondary electrons generated by the iodine atoms during exposure can be confirmed, and the effect is attracting attention in EUV lithography. Patent document 2 describes a photoacid generator in which an iodine atom is introduced into an anion, and patent document 3 describes a photoacid generator containing a polymerizable group in which an iodine atom is introduced into an anion. This confirmed some improvement in lithographic performance, but the organic solvent of iodine atoms had high solubility and was likely to precipitate in the solvent. Patent documents 4 and 5 describe onium salt type monomers having acenaphthene and maleimide as polymerizable groups and producing halothane sulfonic acid. Patent document 6 describes an acenaphthene sulfonic acid-generating onium salt type monomer. According to these descriptions, there is some progress in improvement of lithographic performance but there is room for improvement, and development of a resist material more effective for formation of fine patterns has been sought. Prior art literature Patent literature [ Patent document 1] Japanese patent publication No. 4425776 [ Patent document 2] Japanese patent publication No. 6720926 [ Patent document 3] Japanese patent publication No. 6973274 [ Patent document 4] Japanese patent application laid-open No. 2024-137079 [ Patent document 5] Japanese patent application laid-open No. 2024-112755 [ Patent document 6] International publication No. 2022/172689 Disclosure of Invention [ Problem to be solved by the invention ] Among chemically amplified resist compositions using an acid as a catalyst, development of res