Resist Composition Acid Generator for LWR Reduction
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Solution Overview
Problem
As microelectronic devices approach the diffraction limit, the reduction in pattern feature size leads to lower light contrast, increased line width roughness (LWR), and critical dimension uniformity (CDU) issues due to acid segregation and diffusion in resist films, making it challenging to achieve high sensitivity and resolution simultaneously.
Innovation Solution
A resist composition incorporating a sulfonium or iodonium salt of fluorobenzenesulfonic acid bonded to iodized benzoic acid is used, which suppresses acid diffusion and improves compatibility with the polymer, resulting in reduced LWR and enhanced CDU, while maintaining high sensitivity and resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pattern feature size is reduced to meet higher integration density, then the operating speed and integration density improve, but the light contrast lowers and resolution deteriorates
Solution Approach 1:
The patent changes the chemical parameters of the resist system by introducing a novel acid generator (sulfonium or iodonium salt of fluorobenzenesulfonic acid bonded to iodized benzoic acid) and adjusting the base polymer composition to achieve better pattern fidelity at reduced dimensions
Solution Approach 2:
The patent uses a composite resist formulation combining a specific base polymer with the novel acid generator and quencher components, creating a multi-component system that addresses both resolution and sensitivity requirements for advanced node lithography
2Manufacturing precision
If the acid diffusion distance is reduced to reduce LWR, then the line width roughness improves, but the sensitivity becomes lower
Solution Approach 1:
The patent optimizes the acid diffusion distance parameter by controlling the molecular weight and structure of the base polymer, while simultaneously adjusting the acid generator concentration to maintain high sensitivity despite reduced diffusion
Solution Approach 2:
The patent creates local quality differences in the resist film by positioning the acid generator and base polymer with specific compatibility characteristics, allowing controlled acid diffusion in regions where it benefits sensitivity while limiting diffusion in regions where it would increase LWR
3Manufacturing precision
If the PEB temperature is lowered to reduce LWR, then the line width roughness improves, but the sensitivity becomes lower
Solution Approach 1:
The patent changes the chemical composition parameters of the resist system, specifically the base polymer and acid generator compatibility, to enable effective LWR control at lower PEB temperatures without sacrificing the chemical amplification efficiency that provides sensitivity
4Manufacturing precision
If the amount of quencher added is increased to reduce LWR, then the line width roughness improves, but the sensitivity becomes lower
Solution Approach 1:
The patent optimizes the quencher concentration parameter within a specific range, balancing the LWR reduction benefit from enhanced acid diffusion control against the sensitivity loss from excessive acid neutralization
Solution Approach 2:
The patent uses the quencher component to copy or replicate the beneficial LWR control effect achieved through polymer- acid generator compatibility, providing an additional mechanism for LWR suppression that works synergistically with the primary compatibility mechanism
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resist composition achieves high sensitivity, reduced LWR, and improved CDU, effectively addressing the tradeoff between sensitivity and LWR, and is applicable to both positive and negative tone pattern formation.
Implementation Method 1
the sulfonium or iodonium salt of fluorobenzenesulfonic acid bonded to iodized benzoic acid
Implementation Method 2
the diffusion of generated acid
Data Source
AI summary
A resist composition comprising a base polymer and a sulfonium or iodonium salt capable of generating fluorobenzenesulfonic acid bonded to iodized benzoic acid offers a high sensitivity and minimal LWR independent of whether it is of positive or negative tone.