Radiation-Sensitive Resin Composition for High-Resolution Lithography
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Solution Overview
Problem
Current radiation-sensitive resin compositions face challenges in achieving high resolution and reducing nano-edge roughness for sub-half-micron device designs, particularly with the drawbacks of perfluoroalkylsulfonyl structures that pose environmental and health concerns, and exhibit mask dependence and insufficient surface smoothness.
Innovation Solution
A radiation-sensitive resin composition incorporating a resin with a repeating unit derived from a polymerizable onium sulfonate having a specific structure, which generates an acid with appropriate properties for high resolution and reduced mask dependence, and forms a resist film with excellent surface and sidewall smoothness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a radiation-sensitive acid generator having a perfluoroalkylsulfonyl structure (e.g., PFOS) is used, then the photoresist exhibits sufficiently high resolution with acid having high acidity and appropriate diffusion length, but the composition causes environmental problems due to low combustibility and potential accumulation in human body
Solution Approach 1:
The patent changes the chemical structure parameters of the radiation-sensitive acid generator by replacing perfluoroalkyl groups with alternative structures (such as fluorinated cyclic carbonate groups or other non-perfluoroalkyl fluorinated groups) that can still generate acids with appropriate strength and diffusion length but without the environmental harm of PFOS
Solution Approach 2:
The patent seeks to replace persistent environmental contaminants (PFOS) with shorter-lived, more environmentally benign alternatives that degrade more readily and do not accumulate in the environment or human body
2Manufacturing precision
If a radiation-sensitive acid generator having a trifluoromethanesulfonyl structure is used, then the photoresist exhibits sufficiently high resolution, but the photoresist shows high mask dependence since the acid generated has a low boiling point and inadequate diffusion length
Solution Approach 1:
The patent modifies the acid generator structure to change the physical and chemical parameters of the generated acid, specifically increasing the boiling point and adjusting the diffusion length by using alternative fluorinated structures that provide better thermal stability and controlled diffusion characteristics
3Reliability
If a radiation-sensitive acid generator having a sulfonyl structure bonded to a large organic group (e.g., 10-camphorsulfonyl) is used, then the acid generated has a sufficiently high boiling point and adequate diffusion length showing reduced mask dependence, but the photoresist exhibits insufficient resolution since the acid has insufficient acidity
Solution Approach 1:
The patent optimizes the balance between acid strength and diffusion characteristics by carefully selecting fluorinated group configurations that provide both sufficient acidity for high resolution and appropriate boiling point/diffusion length for reduced mask dependence
Solution Approach 2:
The patent creates composite molecular structures that combine fluorinated groups with cyclic carbonate or other structural elements to achieve a synergistic effect where the combination provides both the necessary acid strength and the appropriate thermal/diffusion properties
4Productivity
If existing radiation-sensitive resin compositions are used for sub-half-micron device designs, then the lithographic process can be performed, but the photoresist exhibits nano-edge roughness and insufficient surface smoothness
Solution Approach 1:
The patent changes the chemical composition parameters of the radiation-sensitive resin to improve the uniformity and smoothness of the developed resist surface, thereby reducing nano-edge roughness and enabling better sub-half-micron patterning
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 composition achieves high resolution, reduced nano-edge roughness, and improved surface smoothness, addressing the limitations of existing technologies while being environmentally friendly and minimizing mask dependence.
Implementation Method 1
a lithographic process utilizing radiation having a wavelength shorter than that of near ultraviolet radiation has been studied... a composition that utilizes a chemical amplification effect due to a component having an acid-dissociable functional group and a radiation-sensitive acid generator... generating an acid upon exposure to radiation
Implementation Method 2
The acid generated by the radiation-sensitive acid generator must have sufficiently high acidity, a sufficiently high boiling point, and an appropriate diffusion length in the resist film... the exposed area of the resist film formed of the composition is easily dissolved in an alkaline developer
Data Source
AI summary
A radiation-sensitive resin composition includes a resin that includes a repeating unit shown by the following formula (1) and a solvent. The radiation-sensitive resin composition has an excellent performance as a radiation-sensitive acid generator, includes a resin that adversely affects the environment and a human body to only a small extent, and can form a resist film that has a high resolution and forms an excellent resist pattern.wherein R1 represents a hydrogen atom or the like, M+ represents a specific cation, and n represents an integer from 1 to 5.