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KR-20260064569-A - POLYMER, CHEMICALLY AMPLIFIED RESIST COMPOSITION, AND PATTERN FORMING METHOD

KR20260064569AKR 20260064569 AKR20260064569 AKR 20260064569AKR-20260064569-A

Abstract

The objective of the present invention is to provide a polymer used in a chemical amplification resist composition having excellent solvent solubility, high sensitivity, high contrast, and excellent lithography performance such as EL, LWR, CDU, and DOF in photolithography using high energy rays, a chemical amplification resist composition containing said polymer, and a pattern forming method using said chemical amplification resist composition. A polymer comprising repeating unit a represented by the following formula (a) and repeating unit b represented by the following formula (b).

Inventors

  • 후쿠시마, 마사히로
  • 오토모, 유타로

Assignees

  • 신에쓰 가가꾸 고교 가부시끼가이샤

Dates

Publication Date
20260507
Application Date
20251027
Priority Date
20241030

Claims (14)

  1. A polymer comprising a repeating unit a represented by the following formula (a) and a repeating unit b represented by the following formula (b). (In the equation, a1 is 0 or 1. a2 is 0, 1, 2, 3 or 4. a3 is 0, 1, 2, 3 or 4. RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R1 is a hydrocarbyl group having 1 to 20 carbon atoms that may include a halogen atom, a nitro group, a cyano group, a hydroxyl group, or a heteroatom. Additionally, when a2 is 2, 3, or 4, multiple R1s may bond to each other to form a ring together with the carbon atoms to which they bond. X 1 is a single bond, -O- or -N(H)-. Q1 to Q4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. Z + is an onium cation. (In the equation, b1 is 1, 2, 3, or 4. b2 is 0, 1, 2, 3, or 4. provided that 1 ≤ b1 + b2 ≤ 5. R A are, respectively, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y1 is a single bond or *-C(=O)-O-. * indicates a bond loss with a carbon atom in the main chain. R11 is a halogen atom, a carboxyl group, a nitro group, a cyano group, a hydrocarbyl group having 1 to 20 carbon atoms that may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms that may contain a heteroatom, a hydrocarbylcarbonyl group having 2 to 20 carbon atoms that may contain a heteroatom, a hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms that may contain a heteroatom, or a hydrocarbyloxycarbonyl group having 2 to 20 carbon atoms that may contain a heteroatom. When b2 is 2, 3, or 4, each R11 may be the same or different from one another.
  2. A polymer according to claim 1, wherein the repeating unit a is represented by the following formula (a1). (In the formula, a1 to a3, R A , R 1 , Q 1 to Q 4 , and Z + are the same as above.)
  3. A polymer in which, in paragraph 2, the repeating unit a is represented by the following formula (a2). (In the formula, a1, a2, R A , R 1 , Q 2 to Q 4 and Z + are the same as above.)
  4. A polymer 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). (In the formula, Rct1 to Rct5 are each independently hydrocarbyl groups having 1 to 30 carbon atoms that may contain a halogen atom or a heteroatom. Additionally, Rct1 and Rct2 may bond to each other to form a ring together with the sulfur atom to which they bond.)
  5. A polymer according to claim 1, wherein Z + is a sulfonium cation represented by the following formula (Z-3). (In the equation, 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. provided that when m1 is 0, 0 ≤ m6 + m9 ≤ 4, and m1 is When m2 is 1, 0 ≤ m6 + m9 ≤ 6. When m2 is 0, 0 ≤ m7 + m10 ≤ 4, and when m2 is 1, 0 ≤ m7 + m10 ≤ 6. When m3 is 0, 1 ≤ m4 + m5 + m8 + m14 ≤ 4, and when m3 is 1, 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, 0 ≤ m12 + m13 ≤ 4, and when m11 is 1, 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1. FR1 to FR3 are each independently a fluorine atom, a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbyloxy group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbylthio group having 1 to 6 carbon atoms. When m5 is 2, 3, or 4, each FR1 may be the same or different from each other. When m6 is 2, 3, 4, 5, or 6, each FR2 may be the same or different from each other. When m7 is 2, 3, 4, 5, or 6, each FR3 may be the same or different from each other. R ct6 to R ct9 are halogen atoms other than iodine and fluorine atoms, nitro groups, cyano groups, hydrocarbyl groups having 1 to 20 carbon atoms that may contain heteroatoms, hydrocarbyloxy groups having 1 to 20 carbon atoms that may contain heteroatoms, or hydrocarbylthio groups having 1 to 20 carbon atoms that may contain heteroatoms. When m8 is 2, the two R ct6s may be identical or different from each other, and the two R ct6s may bond together to form a ring with the carbon atoms to which they bond. When m9 is 2, the two R ct7s may be identical or different from each other, and the two R ct7s may bond together to form a ring with the carbon atoms to which they bond. When m10 is 2, the two R ct8s may be identical or different, and the two R ct8s may bond together to form a ring with the carbon atom to which they bond. When m13 is 2, the two R ct9s may be identical or different, and the two R ct9s may bond together to form a ring with the carbon atom to which they bond. In addition, aromatic rings that directly bind to S + in the sulfonium cation may bond with each other to form a ring together with S + . L A and L B are, independently, single bonds, ether bonds, ester bonds, amide bonds, sulfonic acid ester bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. XL is a hydrocarbylene group having 1 to 40 carbon atoms that may contain single bonds or heteroatoms.
  6. A polymer according to claim 1, further comprising at least one selected from a repeating unit represented by the following formula (c1), a repeating unit represented by the following formula (c2), and a repeating unit represented by the following formula (c3). (In the formula, c1 is 0, 1, 2, 3, or 4. R A are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z1 is a single bond, a phenylene group, a naphthylene group, *-C(=O) -OZ11- or *-C(=O)-NH- Z11- , and the phenylene group or naphthylene group may be substituted with a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbyl group having 1 to 10 carbon atoms that may include a fluorine atom, a saturated hydrocarbyloxy group having 1 to 10 carbon atoms that may include a fluorine atom, or a halogen atom. Z11 is a saturated hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group, or a naphthylene group, and the saturated hydrocarbylene group may include a hydroxyl group, an ether bond, an ester bond, or a lactone ring. Z 2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * indicates the bond loss with carbon atoms in the main chain. R 21 is a hydrocarbyl group having 1 to 20 carbon atoms that may contain a halogen atom, a cyano group, a hydroxyl group, a nitro group, a hydrocarbyl group having 1 to 20 carbon atoms that may contain a heteroatom, a hydrocarbylcarbonyl group having 2 to 20 carbon atoms that may contain a heteroatom, a hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms that may contain a heteroatom, or a hydrocarbyloxycarbonyl group having 2 to 20 carbon atoms that may contain a heteroatom. When c1 is 2, 3, or 4, each R 21 may be the same or different from one another. AL1 and AL2 are, independently, acid instability groups. (In the equation, c11 is 0 or 1. c12 is 0, 1, 2 or 3 when c11 is 0, and 0, 1, 2, 3, 4 or 5 when c11 is 1. RA is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z3 is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * indicates a bond loss with a carbon atom in the main chain. Z 4 is a single bond, an aliphatic hydrocarbylene group having 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a combination thereof. Z 5 and Z 6 are each independently an oxygen atom or a sulfur atom. However, Z 4 and Z 6 have an aromatic ring bonded to an adjacent carbon atom. R22 and R23 are each independently hydrocarbyl groups having 1 to 20 carbon atoms, which may contain a hydrogen atom or a heteroatom. Additionally, R22 and R23 may bond to each other to form a ring together with the carbon atom to which they bond. R24 is a halogen atom, a hydroxyl group, a cyano group, a nitro group, a hydrocarbyl group having 1 to 20 carbon atoms that may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms that may contain a heteroatom, a hydrocarbyloxycarbonyl group having 2 to 20 carbon atoms that may contain a heteroatom, a hydrocarbylthio group having 1 to 20 carbon atoms that may contain a heteroatom, or -N( R24A )( R24B ). R24A and R24B are each independently a hydrogen atom or a hydrocarbyl group having 1 to 6 carbon atoms. When c12 is 2 or more, each R24 may be identical or different from one another, and multiple R24s may bond to each other to form a ring together with the carbon atom of the aromatic ring to which they are bonded.
  7. In claim 1, additionally, a polymer comprising a repeating unit represented by the following formula (d). (In the formula, R A is, each independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 31 is a group having 1 to 20 carbon atoms comprising at least one structure selected from a hydrogen atom, or 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 sulfonic acid ester bond, a carbonate bond, a lactone ring, a sulfone ring, and a carboxylic acid anhydride (-C(=O)-OC(=O)-).
  8. A chemical amplification resist composition comprising (A) a base polymer comprising a polymer comprising any one of claims 1 to 7.
  9. In claim 8, additionally, (B) a chemical amplification resist composition comprising an organic solvent.
  10. In claim 8, additionally, (C) a chemical amplification resist composition comprising ??.
  11. In claim 8, additionally, (D) a chemical amplification resist composition comprising a photoacid generator.
  12. In claim 8, additionally, (E) a chemical amplification resist composition comprising a surfactant.
  13. A pattern forming method comprising: a process of forming a resist film on a substrate using a chemically amplified resist composition described in claim 8; a process of exposing the resist film to high-energy rays; and a process of developing the exposed resist film using a developer.
  14. A pattern forming method according to claim 13, wherein the high-energy line is KrF excimer laser light, ArF excimer laser light, electron beam, or extreme ultraviolet light with a wavelength of 3 to 15 nm.

Description

Polymer, Chemically Amplified Resist Composition, and Pattern Forming Method The present invention relates to a polymer, a chemical amplification resist composition, and a pattern forming method. Along with the high integration and high speed of LSIs, the miniaturization of pattern rules is progressing rapidly. In particular, the expansion of the flash memory market and the increase in memory capacity are driving this miniaturization. As for cutting-edge miniaturization technology, mass production of 65 nm node devices using ArF lithography is underway, and preparations for mass production of 45 nm node devices using next-generation ArF immersion lithography are in progress. For next-generation 32 nm node devices, immersion lithography using an ultra-high NA lens combining a liquid with a higher refractive index than water, a high refractive index lens, and a high refractive index resist film, extreme ultraviolet (EUV) lithography with a wavelength of 13.5 nm, and double exposure (double patterning lithography) of ArF lithography are candidates and are currently under review. As miniaturization progresses and approaches the diffraction limit of light, the light contrast decreases. Due to the decrease in light contrast, in positive-type resist films, the resolution of hole patterns or trench patterns and the focus margin decrease. With the miniaturization of patterns, line width roughness (LWR) and hole pattern dimensional uniformity (CDU) are becoming problematic. The effects of localization or aggregation of base polymers or acid generators, as well as the influence of acid diffusion, have been pointed out. Furthermore, LWR tends to increase with the thinning of the resist film, and the degradation of LWR caused by thinning accompanying miniaturization is becoming a serious issue. In resist compositions for EUV lithography, it is necessary to simultaneously achieve high sensitivity, high resolution, and low LWR. Shortening the acid diffusion distance reduces LWR but lowers sensitivity. For example, lowering the post-exposure baking (PEB) temperature reduces LWR but lowers sensitivity. Increasing the amount of additive also reduces LWR but lowers sensitivity. It is necessary to overcome the trade-off relationship between sensitivity and LWR. To suppress acid diffusion, a resist compound comprising a polymer containing repeating units derived from an onium salt of a sulfonic acid having polymerizable unsaturated bonds has been proposed (Patent Document 1). Since such so-called polymer-linked acid generators generate polymeric sulfonic acid upon exposure, they are characterized by very short acid diffusion. Additionally, sensitivity can be improved by increasing the proportion of the acid generator. In the case of additive acid generators, increasing the amount added also leads to high sensitivity, but in this case, the acid diffusion distance also increases. Since acid diffuses non-uniformly, increased acid diffusion leads to the deterioration of the LWR or CDU. It can be said that polymeric acid generators possess high capability in terms of the balance of sensitivity, LWR, and CDU. Since iodine atoms have a very high absorption rate of EUV with a wavelength of 13.5 nm, the effect of secondary electron generation from iodine atoms during exposure has been confirmed and is receiving attention in EUV lithography. Patent Document 2 describes a photoacid generator in which iodine atoms are introduced into an anion, and Patent Document 3 describes a photoacid generator containing polymerizable groups in which iodine atoms are introduced into anion. Although some improvement in lithography performance has been confirmed by this, iodine atoms do not have high solubility in organic solvents, so there is a concern about precipitation in the solvent. Figure 1 is the nuclear magnetic resonance spectrum ( 1 H-NMR/DMSO-d 6 ) of monomer PAG-1 synthesized in Example 1-1. The present invention will be described in detail below. In addition, in the following description, depending on the structure represented by the chemical formula, an asymmetric carbon may be present, and enantiomers or diastereomers may be present; however, in such cases, the isomers are represented by a single formula. The isomers may be used as a single type or as a mixture of two or more types. [Polymer] The polymer of the present invention comprises a repeating unit represented by the following formula (a) (hereinafter also referred to as repeating unit a). In formula (a), a1 is 0 or 1. When a1 is 0, it is a benzene ring, and when a1 is 1, it is a naphthalene ring, but from the perspective of solvent solubility, it is preferable that a1 is a benzene ring of 0. a2 is 0, 1, 2, 3, or 4, but from the perspective of raw material procurement, it is preferable that it is 0 or 1. a3 is 0, 1, 2, 3, or 4, but from the perspective of raw material procurement, it is preferable that it is 1 to 3. In formula (a), R A is a hydrogen atom, a fluorine atom, a methyl g