EUV Resist Underlayer Film Composition for Pattern Shape Accuracy
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Solution Overview
Problem
EUV lithography techniques face challenges in forming good, straight-shaped resist patterns due to adverse effects from substrates and EUV, requiring resist underlayer films that enhance sensitivity and etching rates while preventing intermixing with resist layers and diffusing low molecular weight materials.
Innovation Solution
A resist underlayer film composition comprising a polymer with a specific repeating unit structure, a crosslinkable compound, and a solvent, which forms a thin film with a high etching rate and excellent adhesion, reducing substrate and EUV adverse effects and enhancing pattern formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional photolithographic techniques using ArF excimer lasers are used, then existing photoresist patterns can be formed, but diffused reflections and standing waves occur from the substrate, causing shape distortion
Solution Approach 1:
The patent introduces an organic anti-reflective coating as an intermediary layer between the photoresist and substrate. This coating contains light-absorbing substances that prevent diffused reflections and standing waves from the substrate, thereby improving pattern shape accuracy without requiring complex vacuum deposition or sputtering equipment
Solution Approach 2:
The organic anti-reflective coating is formulated as a composite material containing both light-absorbing substances and macro molecule compounds. This composite structure provides both anti-reflective properties and structural integrity, enabling effective reflection prevention while maintaining film stability during processing
2Object-affected harmful factors
If inorganic anti-reflective coatings are used to prevent reflection, then reflection is effectively reduced, but special vacuum deposition devices, CVD devices, or sputtering devices are required
Solution Approach 1:
The patent replaces complex mechanical vacuum deposition and sputtering systems with a chemically formulated organic coating solution. The organic anti-reflective coating can be applied using standard spin-coating equipment, eliminating the need for expensive vacuum chambers and plasma generation systems while achieving comparable or superior anti-reflective performance
3Manufacturing precision
If EUV lithography is used to achieve finer processing, then wavelength is reduced to 13.5 nm, but adverse effects from substrates and EUV cause flare and undercut in resist patterns
Solution Approach 1:
The patent introduces a resist underlayer film as an intermediary between the EUV resist and substrate. This underlayer film absorbs excess EUV radiation and prevents it from interacting with the resist in ways that cause flare and undercut, thereby maintaining the fine processing capabilities of EUV lithography while eliminating the associated defects
Solution Approach 2:
The patent modifies the optical and chemical parameters of the resist system by introducing the underlayer film with specific absorption characteristics. The underlayer film's optical density and chemical composition are optimized to absorb EUV radiation at wavelengths that would otherwise cause harmful effects, changing the overall interaction parameters between EUV light, resist, and substrate
4Manufacturing precision
If EUV lithography is used, then next-generation fine processing is achieved, but sensitivity to EUV is too low to obtain sufficient throughput
Solution Approach 1:
The patent optimizes the chemical composition parameters of the resist and underlayer film to enhance EUV sensitivity. By adjusting the molecular weight, functional groups, and crosslinking density of the polymer components, the resist becomes more responsive to EUV exposure, reducing the required exposure dose and thereby increasing throughput while maintaining fine processing capability
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 allows for the formation of clear, straight-shaped resist patterns with increased sensitivity and improved etching rates, effectively addressing the limitations of conventional EUV lithography by reducing substrate and EUV-induced defects.
Implementation Method 1
a polymer having a repeating unit structure of formula (1)... large absorbance to light and radiation
Implementation Method 2
a crosslinkable compound... no intermixing with photoresist layers (insoluble in resist solvents)
Implementation Method 3
resist underlayer film-forming composition for EUV lithography containing condensation polymer
Data Source
AI summary
There is provided a resist underlayer film composition for EUV lithography that is used in a device production process using EUV lithography, reduces adverse effects of EUV, and is effective for obtaining a good resist pattern, and to a method for forming a resist pattern that uses the resist underlayer film composition for EUV lithography. A resist underlayer film-forming composition for EUV lithography, including: a polymer having a repeating unit structure of formula (1):[where each of A1, A2, A3, A4, A5, and A6 is a hydrogen atom, a methyl group, or an ethyl group; X1 is formula (2), formula (3), formula (4), or formula (0):Q is formula (5) or formula (6):and a solvent. A resist underlayer film-forming composition for EUV lithography, comprising: the polymer having the repeating unit structure of formula (1); a crosslinkable compound; and a solvent.