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US 11,333,974 B2Granted
Onium salt, chemically amplified resist composition, and patterning process
AssigneeShin-Etsu Chemical Co., Ltd.
InventorMasahiro Fukushima
Life of this patent
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Abstract
A novel onium salt and a resist composition comprising the same as a PAG are provided. When processed by photolithography using KrF or ArF excimer laser, EB or EUV, the resist composition is reduced in acid diffusion and improved in exposure latitude, MEF, and LWR.
Claims21
An onium salt having the formula (1):
- wherein Z is a monocyclic or polycyclic group having a lactam structure,
- Rf1 to Rf4 are each independently hydrogen, fluorine or trifluoromethyl, at least one of Rf1 to Rf4 being fluorine or trifluoromethyl,
- R1 is hydrogen or a C1-C20 monovalent hydrocarbon group which may contain a heteroatom,
- R2 is a C1-C20 monovalent hydrocarbon group which may contain a heteroatom,
- L1, L2 and L3 are each independently a single bond, ether bond, ester bond, sulfonic acid ester bond, carbonate bond or carbamate bond,
- L4 is an ether bond, ester bond, sulfonic acid ester bond, carbonate bond or carbamate bond,
- X1 is a single bond or a C1-C40 divalent hydrocarbon group which may contain a heteroatom,
- n1 is an integer of 0 to 6, with the proviso that R1 and R2 may bond together to form a ring structure when n1 is 1 and R1 is not hydrogen, and two R1 may bond together to form a ring structure when n1 is an integer of at least 2 and R1 is not hydrogen, and
- Q+ is an onium cation.
6 more elements
Dependencies are inferred from the claim text.