Fluorene-Based Polymer Resist Underlayer Film for Semiconductor Lithography
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Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in achieving high etching resistance, thermal stability, and coating uniformity for resist underlayer films, particularly at the 30 nm node or less, due to limitations in existing photoresist materials and hard mask technologies, which affect pattern resolution and stability during high-temperature processes.
Innovation Solution
A novel fluorene-based polymer with a specific repeating unit is developed, providing excellent thermal stability, etching resistance, and coating uniformity, along with high solubility to organic solvents, enabling improved storage stability and line compatibility, and is used to form a resist underlayer film through spin-on coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a CVD process is used to form an inorganic underlayer film, then etching resistance is improved, but manufacturing cost and process complexity increase
Solution Approach 1:
The patent replaces the CVD mechanical deposition process with a spin-coating process that applies a polymer-based organic underlayer film. This substitution eliminates the need for complex CVD equipment while achieving comparable etching resistance through the polymer's chemical composition and film-forming properties
Solution Approach 2:
The patent changes the material parameters from inorganic CVD deposits to organic polymer materials with specific molecular structures. The polymer composition parameters (monomer selection, molecular weight, functional groups) are optimized to achieve the required etching resistance that previously required inorganic materials
2Manufacturing precision
If the photoresist film thickness is reduced to achieve high resolution, then pattern resolution is improved, but etching capability deteriorates
Solution Approach 1:
The patent introduces a polymer-based underlayer film as an intermediary between the photoresist and the substrate. This intermediate layer has optimized thickness and material properties that enable effective etching transmission while allowing the photoresist to maintain thin dimensions for high-resolution patterning
Solution Approach 2:
The patent employs composite material structures combining the polymer underlayer with the photoresist layer. The composite system leverages the polymer's etching resistance and the photoresist's patterning capability, achieving both high resolution and effective etching that neither material could achieve alone
3Reliability
If polymer carbon content is increased to improve etching resistance, then etching resistance is improved, but solubility to organic solvents deteriorates
Solution Approach 1:
The patent applies local quality by incorporating polar functional groups at specific locations within the polymer molecular structure. These localized polar regions provide solubility to organic solvents while the overall high carbon content of the polymer backbone maintains etching resistance, resolving the contradiction between these two properties
Solution Approach 2:
The patent creates composite polymer structures combining hydrophobic carbon-rich segments for etching resistance with hydrophilic polar functional groups for solubility. This molecular-level composite structure enables the polymer to exhibit both high etching resistance and good solubility properties simultaneously
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 fluorene-based polymer enhances etching resistance, thermal stability, and coating uniformity, improving storage stability and line compatibility, and allows for effective gap-fill and planarization, making it suitable for high-resolution semiconductor lithography processes.
Implementation Method 1
a resist underlayer film composition containing the polymer, and a method for forming a resist underlayer film using the composition
Data Source
AI summary
Provided are a fluoreneol-based monomer, a polymer for preparing a resist underlayer film obtained therefrom, a resist underlayer film composition containing the polymer, and a method for forming a resist underlayer film using the resist underlayer film composition, wherein the fluoreneol-based monomer is represented by Chemical Formula 2 below: