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US 12,240,804 B2Granted
Onium salt, chemically amplified resist composition and patterning process
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsTakayuki Fujiwara, Satoshi Watanabe, Kousuke Ohyama
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Abstract
An onium salt having formula (1) serving as an acid diffusion inhibitor and a chemically amplified resist composition comprising the acid diffusion inhibitor are provided. When processed by lithography, the resist composition forms a pattern having minimal defects and excellent lithography performance factors such as CDU, LWR and DOF.
Claims15
A chemically amplified resist composition comprising:
- (A) a base polymer comprising repeat units having the formula (a) or repeat units having the formula (b),
- (B) a photoacid generator,
- (C-1) an acid diffusion inhibitor comprising an onium salt having the formula (1), and
- (D) an organic solvent,
- wherein X is sulfur,
- n is 1 when X is sulfur,
- R1 is a C1-C5 straight or branched hydrocarbyl group in which at least one of hydrogen atoms of the C1-C5 straight or branched hydrocarbyl group may be replaced with fluorine or in which at least one of carbons which is not terminal may be replaced with oxygen to form an ether, and R1 is exclusive of a tertiary hydrocarbyl group,
- R2 and R3 are each independently a C1-C30 hydrocarbyl group which may contain fluorine, chlorine, bromine, iodine, cyano moiety, carbonyl moiety, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sultone ring, carboxylic anhydride or haloalkyl moiety, R2 and R3 may bond together to form a ring with X to which they are attached,
- Ar is a C6-C14 arylene group which may be substituted with a substituent selected from a halogen atom, hydroxy group, C1-C10 hydrocarbyl group which may contain a heteroatom, C1-C10 hydrocarbyloxy group which may contain a heteroatom, C2-C10 hydrocarbylcarbonyl group which may contain a heteroatom, and C2-C10 hydrocarbylcarbonyloxy group which may contain a heteroatom, R2 and Ar may bond together to form a ring with X to which they are attached, wherein Ar does not include a hydroxyl group, and
- Z− is a carboxylate, sulfonamide, sulfonimide or methide anion,
- wherein RA is each independently hydrogen or methyl,
- XA is a single bond, phenylene group, naphthylene group or (backbone)-C(═O)—O—XA1—, XA1 is a C1-C15 hydrocarbylene group which may contain a hydroxy moiety, ether bond, ester bond, or lactone ring,
- XB is a single bond or ester bond,
- AL1 and AL2 are each independently an acid labile group.
11 more elements
A chemically amplified resist composition comprising:
- (A′) a base polymer comprising repeat units having the formula (a) or repeat units having the formula (b) and repeat units adapted to generate an acid upon light exposure,
- (C-1) the acid diffusion inhibitor, comprising an onium salt having the formula (1), and
- (D) an organic solvent,
- wherein X is sulfur,
- n is 1 when X is sulfur,
- R1 is a C1-C5 hydrocarbyl group which may contain fluorine or oxygen,
- R2 and R3 are each independently a C1-C30 hydrocarbyl group which may contain a heteroatom, R2 and R3 may bond together to form a ring with X to which they are attached,
- Ar is a C6-C14 arylene group which may be substituted with a substituent selected from a halogen atom, hydroxy group, C1-C10 hydrocarbyl group which may contain a heteroatom, C1-C10 hydrocarbyloxy group which may contain a heteroatom, C2-C10 hydrocarbylcarbonyl group which may contain a heteroatom, and C2-C10 hydrocarbylcarbonyloxy group which may contain a heteroatom, R2 and Ar may bond together to form a ring with X to which they are attached, and
- Z− is a carboxylate, sulfonamide, sulfonimide or methide anion,
- wherein RA is each independently hydrogen or methyl,
- XA is a single bond, phenylene group, naphthylene group or (backbone)-C(═O)—O—XA1—, XA1 is a C1-C15 hydrocarbylene group which may contain a hydroxy moiety, ether bond, ester bond, or lactone ring,
- XB is a single bond or ester bond,
- AL1 and AL2 are each independently an acid labile group.
10 more elements
Dependencies are inferred from the claim text.