Sulfonium salt, chemically amplified resist composition, and patterning method
The use of a sulfonium salt with specific aromatic substitutions in a chemically amplified resist composition effectively addresses acid diffusion issues, enhancing lithography performance and pattern formation in high-resolution photolithography.
Patent Information
- Application Number
- JP2024186982
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2026-05-11
AI Technical Summary
Conventional resist compositions using onium salt-type photoacid generators fail to adequately suppress acid diffusion, leading to degradation of lithography performance such as contrast, line width roughness (LWR), critical dimension uniformity (CDU), mask error factor (MEF), exposure margin (EL), and depth of field (DOF), particularly in high-resolution photolithography using high-energy beams like KrF excimer laser light, ArF excimer laser light, electron beam (EB), and EUV.
A sulfonium salt comprising an aromatic sulfonic acid anion substituted with a hydrocarbyl group containing at least one aromatic ring and a sulfonium cation with a pentafluorosulfanyl group and a hydrocarbyloxycarbonyl group is used as a photoacid generator in a chemically amplified resist composition, enhancing solvent solubility, sensitivity, and suppressing acid diffusion, thereby improving lithography performance.
The sulfonium salt-based resist composition exhibits high sensitivity, excellent acid diffusion suppression, and improved lithography performance, including LWR, CDU, MEF, EL, and DOF, enabling the formation of fine patterns with reduced deformation during pattern formation.