Onium salt, chemically amplified resist composition, and patterning process
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsMasahiro Fukushima, Jun Hatakeyama
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Abstract
An onium salt having formula (1) is provided. A chemically amplified resist composition comprising the onium salt as a PAG has improved lithography properties including sensitivity, acid diffusion control, MEF, and LWR when processed by photolithography using high-energy radiation. The resist composition having a high solvent solubility and a high sensitivity and being improved in lithography properties such as EL and LWR when processed by photolithography using high-energy radiation such as KrF or ArF excimer laser, EB or EUV; and a pattern forming process using the resist composition.
Claims17
An onium salt having the formula (1):
- wherein n1 is 0 or 1, n2 is an integer of 1 to 3, n3 is an integer of 1 to 4, meeting 1≤n2+n3≤4 in case of n1=0 and 1≤n2+n3≤6 in case of n1=1, n4 is an integer of 0 to 3, n5 is an integer of 0 to 4,
- R1 is halogen exclusive of iodine or a C1-C20 hydrocarbyl group which may contain a heteroatom,
- R2 is a C1-C20 hydrocarbyl group which may contain a heteroatom,
- XA and XB are each independently a single bond or a divalent linking group containing an ester bond, ether bond, sulfonate ester bond, carbonate bond or carbamate bond,
- R is a C3-C20 (n4+3)-valent cyclic hydrocarbon group which may contain a heteroatom,
- LA and LB are each independently a single bond, ether bond, ester bond, sulfonate ester bond, carbonate bond or carbamate bond,
- XL is a single bond or a C1-C40 hydrocarbylene group which may contain a heteroatom,
- Q1 and Q2 are each independently hydrogen, fluorine or a C1-C6 fluorinated saturated hydrocarbyl group,
- Q3 and Q4 are each independently fluorine or a C1-C6 fluorinated saturated hydrocarbyl group, and
- Z+ is an onium cation.
Dependencies are inferred from the claim text.