Resist Underlayer Composition for Solvent-Resistant Rectangular Patterns
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Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in forming resist underlayer films with excellent solvent resistance and rectangularity, particularly with the advancement to shorter exposure wavelengths, which affects the precision and reliability of semiconductor substrate patterning.
Innovation Solution
A method involving a composition for forming a resist underlayer film, comprising a polymer with a sulfonimide salt structure and a solvent, applied to a substrate, followed by exposure and development, enhances solvent resistance and pattern rectangularity, enabling efficient semiconductor substrate manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional resist underlayer film compositions are used, then the manufacturing process is simple, but the solvent resistance and pattern rectangularity are insufficient
Solution Approach 1:
The patent employs composite polymer materials combining polyhydrocinnamic acid ester backbone structures with sulfonimide salt side chains. This composite structure integrates the mechanical stability of the polyester backbone with the acid-generating capability of sulfonimide salts, achieving both solvent resistance and pattern rectangularity in a single formulation without requiring multiple layers or complex additives
Solution Approach 2:
The patent systematically varies the molecular weight, functional group composition, and side chain structure of the polymer to optimize performance. By adjusting parameters such as the ratio of cyclic to linear diol components, the molecular weight range, and the specific sulfonimide salt structure, the formulation achieves maximum solvent resistance and pattern fidelity while maintaining processability
2Manufacturing precision
If conventional resist underlayer film compositions are used, then the formulation is simple, but the pattern rectangularity and shape control are poor
Solution Approach 1:
The patent optimizes the molecular weight of the polymer within a specific range (1,000 to 50,000) to balance film-forming capability and pattern resolution. The molecular weight, functional group composition, and side chain structure are systematically adjusted to enhance acid generation efficiency and solubility control, achieving superior pattern rectangularity without requiring complex multi-component formulations
Solution Approach 2:
The sulfonimide salt groups are positioned as side chains on the polyester backbone, creating local regions of high acid-generation capability at specific sites within the polymer structure. This localized functional arrangement enables precise pattern definition and rectangularity control while maintaining the overall structural integrity and solvent resistance of the film
3Measurement precision
If shorter wavelength exposure light is used, then the resolution is improved, but the acid generation efficiency in the resist underlayer film decreases
Solution Approach 1:
The patent selects sulfonimide salts with specific molecular structures and absorption characteristics that are highly responsive to shorter wavelength radiation (248 nm KrF and 193 nm ArF). By optimizing the aromatic ring substitution patterns and cation structure, the acid generation quantum efficiency is maximized for these wavelengths, enabling effective patterning at higher resolutions
Solution Approach 2:
The patent replaces conventional photoacid generators with sulfonimide salt-based systems that utilize photolytic decomposition mechanisms more efficient at shorter wavelengths. The sulfonimide salt structure enables direct photolysis at 248 nm and 193 nm, substituting less efficient thermal or indirect photolysis mechanisms, thereby achieving high acid generation efficiency with advanced exposure tools
4Manufacturing precision
If additional etching steps are added to improve pattern shape, then the pattern quality is improved, but the manufacturing complexity and time increase
Solution Approach 1:
The resist underlayer film performs self-pattern definition through controlled acid generation and solubility changes during exposure and development. The sulfonimide salt decomposition and subsequent solubility modification enable the film to automatically form precise patterns without requiring additional etching or pattern transfer steps, maintaining high pattern quality while simplifying the overall manufacturing process
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 method allows for the formation of semiconductor substrates with improved pattern shape and solvent resistance, suitable for advanced semiconductor devices, by promoting acid generation and solubility in developers, thus reducing the need for additional etching steps and enhancing manufacturing efficiency.
Implementation Method 1
exposing the resist film to radiation
Data Source
AI summary
A method includes: applying a composition for forming a resist underlayer film directly or indirectly to a substrate to form a resist underlayer film; applying a composition for forming a resist film to the resist underlayer film to form a resist film; exposing the resist film to radiation; and developing the exposed resist film. The composition for forming a resist underlayer film includes: a polymer including a partial structure represented by formula (i); and a solvent. In the formula (i), Y1 is a sulfonyl group, a carbonyl group, or an alkanediyl group; Y2 is a sulfonyl group, a carbonyl group, or a single bond; when Y1 is an alkanediyl group, Y2 is a sulfonyl group or a carbonyl group, and when Y2 is a single bond, Y1 is a sulfonyl group or a carbonyl group; R1 is a monovalent organic group having 1 to 20 carbon atoms.