Resist Underlayer Film Composition for High Aspect Ratio Patterning
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Solution Overview
Problem
Current underlayer film compositions for semiconductor manufacturing face challenges in achieving reduced reflectance, optimal n-value and k-value, excellent filling-up properties, and preventing line fall or wiggling during etching, especially for high aspect ratio patterns thinner than 60 nm, particularly with the limitations of CVD-C films in filling non-planar substrates and the complexity of CVD equipment.
Innovation Solution
A resist underlayer film composition containing polymers obtained by condensation of specific compounds, such as those represented by general formulas (1-1) and (2), which provide a polymer with controlled n-value and k-value, excellent antireflective, and antibending properties, formed using a spin coating method to avoid wiggling and enhance filling-up capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If CVD-C film is used for underlayer film to achieve etching resistance, then etching resistance is improved, but filling-up property on non-planar substrates deteriorates
Solution Approach 1:
The patent changes the material composition parameters of the underlayer film by incorporating specific polymers (polyester, polyacrylate, polymethacrylate) with controlled glass transition temperatures and molecular weights, along with cyanate esters as crosslinking agents. This composition optimization achieves both high etching resistance and excellent filling-up properties on non-planar substrates without requiring CVD equipment.
2Device complexity
If spin coating method is used to simplify the process, then device complexity is reduced, but film uniformity and precision may deteriorate
Solution Approach 1:
The patent employs a composite material system consisting of polymer base materials (ester, acrylate, or methacrylate polymers), cyanate ester crosslinking agents, and optional additives. This composite formulation enables the spin-coated film to achieve uniform thickness and high precision patterns while maintaining simplicity of the spin coating process, avoiding the need for complex CVD equipment.
3Strength
If underlayer film thickness is increased to improve etching resistance, then etching resistance is improved, but pattern precision deteriorates due to line fall and wiggling
Solution Approach 1:
The patent optimizes the film thickness parameter to a specific range (50-200 nm) and compensates for etching resistance through chemical composition optimization rather than thickness increase. The use of cyanate esters as crosslinking agents creates a dense network structure that provides high etching resistance at reduced thickness, preventing line fall and wiggling while maintaining pattern precision.
4Object-affected harmful factors
If conventional underlayer film composition is used to achieve antireflective function, then antireflective property is improved, but n-value and k-value control becomes complex
Solution Approach 1:
The patent controls the optical parameters (n-value and k-value) by selecting polymers with specific glass transition temperatures and molecular weights, and by optimizing the ratio of cyanate ester crosslinking agents. This systematic parameter control achieves the required antireflective function (n-value: 1.3-1.7, k-value: 0.1-0.5 at 193 nm) while maintaining composition simplicity and ease of manufacturing.
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 precision patterning with reduced reflectance and improved etching resistance, enabling precise pattern formation on non-planar substrates without line fall or wiggling, and simplifies the process by using a spin coating method that avoids the complexity of CVD equipment.
Implementation Method 1
a resist underlayer film composition which contains a polymer obtained by condensation of, at least, one or more compounds represented by general formula (1-1) and/or (1-2), and one or more kinds of compounds and/or equivalent bodies thereof represented by general formula (2)... functions as an excellent antireflective film especially to an exposure light of a short wavelength (i.e., the resist underlayer film is highly transparent)
Implementation Method 2
formed using a spin coating method to avoid wiggling and enhance filling-up capabilities
Data Source
AI summary
There is disclosed a resist underlayer film composition, wherein the composition contains a polymer obtained by condensation of, at least, one or more compounds represented by the following general formula (1-1) and/or (1-2), and one or more kinds of compounds and/or equivalent bodies thereof represented by the following general formula (2). There can be provided an underlayer film composition, especially for a trilayer resist process, that can form an underlayer film having reduced reflectance, namely, an underlayer film having optimum n-value and k-value, excellent filling-up properties, high pattern-antibending properties, and not causing line fall or wiggling after etching especially in a high aspect line that is thinner than 60 nm, and a patterning process using the same.