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KR-102961053-B1 - RESIST COMPOSITION AND PATTERN FORMING PROCESS

KR102961053B1KR 102961053 B1KR102961053 B1KR 102961053B1KR-102961053-B1

Abstract

The present invention provides a resist material that is highly sensitive, whether positive or negative, and has improved LWR or CDU, and a pattern forming method using the same. A resist material comprising a sulfonium salt of one or more compounds selected from N-carbonyltrifluoromethoxybenzenesulfonamide, N-carbonyldifluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide, and difluoromethoxybenzenesulfonimide.

Inventors

  • 하타케야마, 준
  • 후쿠시마, 마사히로

Assignees

  • 신에쓰 가가꾸 고교 가부시끼가이샤

Dates

Publication Date
20260508
Application Date
20240724
Priority Date
20230728

Claims (14)

  1. A ?? process comprising a sulfonium salt of one or more compounds selected from N-carbonyltrifluoromethoxybenzenesulfonamide, N-carbonyldifluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide, and difluoromethoxybenzenesulfonimide, and The above sulfonium salt is a resist material represented by the following formula (1). (In the equation, m is an integer from 1 to 5, and n is an integer from 0 to 4. Provided that 1 ≤ m + n ≤ 5. X 1 is -C(=O)- or -S(=O) 2 -. R1 is a trifluoromethyl group or a difluoromethyl group. R2 is a saturated hydrocarbyl group having 1 to 6 carbon atoms, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, or a halogen atom. R3 is an alkyl group having 1 to 20 carbon atoms, a cyclic unsaturated aliphatic hydrocarbyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, and the group may include at least one selected from oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. R4 to R6 are each independently hydrocarbyl groups having 1 to 20 carbon atoms that may contain a halogen atom or a heteroatom. Additionally, R4 and R5 may bond to each other to form a ring together with the sulfur atom to which they bond.
  2. A resist material in which n is 0, as in claim 1.
  3. A resist material according to claim 1, further comprising a base polymer.
  4. A resist material according to paragraph 3, wherein the base polymer comprises a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2). (In the formula, R A is, independently, a hydrogen atom or a methyl group. Y1 is a linker having 1 to 12 carbon atoms comprising at least one selected from a single bond, a phenylene group or a naphthylene group, or an ester bond, an ether bond, and a lactone ring. Y2 is a single bond or an ester bond. Y3 is a single bond, an ether bond, or an ester bond. R 11 and R 12 are, independently, acid instability groups. R 13 is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R 14 is a single bond or an alkandyl group having 1 to 6 carbon atoms, and a portion of the -CH 2- of the said alkandyl group may be substituted by an ether bond or an ester bond. a is 1 or 2. b is an integer from 0 to 4. Provided that 1 ≤ a + b ≤ 5.
  5. In paragraph 4, a resist material that is a chemically amplified positive type resist material.
  6. A resist material according to paragraph 3, wherein the base polymer does not contain acid unstable groups.
  7. In paragraph 6, a resist material that is a chemically amplified negative type resist material.
  8. A resist material according to claim 3, wherein the base polymer comprises at least one selected from a repeating unit represented by the following formula (f1), a repeating unit represented by the following formula (f2), and a repeating unit represented by the following formula (f3). (In the formula, R A is, independently, a hydrogen atom or a methyl group. Z1 is a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by a combination thereof, or -OZ11- , -C(=O) -OZ11- , or -C(=O)-NH- Z11- . Z11 is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by a combination thereof, and may include a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z2 is a single bond or an ester bond. Z3 is a single bond, -Z31 -C(=O)-O-, -Z31 -O-, or -Z31 -OC(=O)-. Z31 is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may include a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom. Z 4 is a methylene group, 2,2,2-trifluoro-1,1-ethanediyl group, or carbonyl group. Z 5 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -OZ 51- , -C(=O)-OZ 51- , or -C(=O)-NH-Z 51- . Z 51 is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may include a carbonyl group, an ester bond, an ether bond, a halogen atom, or a hydroxyl group. R 21 to R 28 are each independently hydrocarbyl groups having 1 to 20 carbon atoms that may contain a halogen atom or a heteroatom. Additionally, R 23 and R 24 or R 26 and R 27 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. M- is a non-nucleophilic counterion.)
  9. A resist material according to claim 1, further comprising an acid-generating agent that generates a strong acid.
  10. A resist material according to claim 9, wherein the acid generating agent generates sulfonic acid, imidic acid, or methic acid.
  11. A resist material according to claim 1, further comprising an organic solvent.
  12. A resist material according to claim 1, further comprising a surfactant.
  13. A pattern forming method comprising: a process of forming a resist film on a substrate using a resist material described in any one of claims 1 to 12; 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

Resist Composition and Pattern Forming Process The present invention relates to a resist material and a pattern forming method. Along with the high integration and high speed of LSIs, the miniaturization of pattern rules is progressing rapidly. This is because the widespread adoption of 5G high-speed communication and artificial intelligence (AI) is increasing, and high-performance devices are required to process them. As a cutting-edge miniaturization technology, mass production of 5nm node devices is being carried out using extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm. Furthermore, the use of EUV lithography is being considered for next-generation 3nm node and the generation after that 2nm node devices. With the progress of miniaturization, image blurring caused by acid diffusion is becoming a problem. It has been suggested that in order to secure resolution in fine patterns with a size of 45 nm or larger, control of acid diffusion is important, in addition to the improvement of dissolution contrast that has been conventionally proposed (Non-patent Literature 1). However, since chemical amplification resist materials increase sensitivity and contrast through acid diffusion, if one attempts to suppress acid diffusion to the extreme by lowering the post-exposure baking (PEB) temperature or shortening the time, sensitivity and contrast are significantly reduced. The relationship of the triangle trade-off between sensitivity, resolution, and edge roughness (LWR) is shown. To improve resolution, it is necessary to suppress acid diffusion, but sensitivity decreases as the acid diffusion distance becomes shorter. It is effective to suppress acid diffusion by adding an acid-generating agent that generates bulky acid. Therefore, it has been proposed to include repeating units derived from onium salts having polymerizable unsaturated bonds in a polymer. In this case, the polymer also functions as an acid-generating agent (polymer-bound acid-generating agent). Patent Document 1 proposes a sulfonium salt or iodonium salt having polymerizable unsaturated bonds that generates a specific sulfonic acid. Patent Document 2 proposes a sulfonium salt in which a sulfonic acid is directly linked to the main chain. The acid instability group used in (meth)acrylate polymers for ArF resist materials undergoes a deprotection reaction when using a photoacid generator that generates a sulfonic acid in which the α-position is substituted with a fluorine atom, but the deprotection reaction does not proceed with an acid generator that generates a sulfonic acid or carboxylic acid in which the α-position is not substituted with a fluorine atom. When a sulfonium salt or iodonium salt that generates a sulfonic acid in which the α-position is substituted with a fluorine atom is mixed with a sulfonium salt or iodonium salt that generates a sulfonic acid in which the α-position is not substituted with a fluorine atom, the sulfonium salt or iodonium salt that generates a sulfonic acid in which the α-position is not substituted with a fluorine atom undergoes ion exchange with the sulfonic acid in which the α-position is substituted with a fluorine atom. Since sulfonic acids in which the α-site is substituted with a fluorine atom by light are reversed to sulfonium salts or iodonium salts by ion exchange, sulfonium salts or iodonium salts of sulfonic acids or carboxylic acids in which the α-site is not substituted with a fluorine atom function as etchants. A resist material has been proposed that uses a sulfonium salt or iodonium salt that generates a carboxylic acid as an etchant (Patent Document 3). Sulfonamides have an acidity close to that of carboxylic acids, and these sulfonium salts function as sulfonamide-based sulfonium salts. Sulfonium salt-type sulfonamide-based sulfonamide-based sulfonamides have been proposed (Patent Documents 4 to 6). It has been pointed out that the dimensional uniformity of the resist pattern is reduced due to the aggregation of bleeds. It is expected that the dimensional uniformity of the pattern after development will be improved by preventing the aggregation of bleeds in the resist film and making the distribution uniform. The health effects of perfluoroalkyl compounds (PFAS) have been pointed out, and there are movements to establish restrictions on the manufacture and sale of PFAS under the European REACH. In the field of semiconductor lithography, many compounds containing PFAS are currently used. For example, materials containing them are applied in surfactants, acid generators, and etchants. [Resist Material] The resist material of the present invention comprises a sulfonium salt (hereinafter also referred to as sulfonium salt A) of one or more compounds selected from N-carbonyltrifluoromethoxybenzenesulfonamide, N-carbonyldifluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide, and difluoromethoxybenzenesulfonimide. [??wife] Sulfonium salt A is preferably represented by