Resist Topcoat Composition for EUV Pattern Roughness Control
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Solution Overview
Problem
Photolithographic processes in semiconductor manufacturing face issues such as pattern distribution deterioration due to EUV irradiation, leading to roughness and uniformity problems in photoresist patterns.
Innovation Solution
A resist topcoat composition comprising a copolymer with specific structural units and a photoacid generator, which increases acid generation in exposed regions, improving sensitivity and reducing energy requirements for pattern formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If EUV irradiation is applied to photoresist, then pattern formation is achieved, but pattern distribution deteriorates due to photo shot noise and absorption differences
Solution Approach 1:
A topcoat layer is introduced as an intermediary between the EUV light source and the photoresist layer. This topcoat absorbs excess EUV energy and generates photoacids that diffuse into the photoresist, mediating the interaction between EUV irradiation and photoresist to reduce shot noise effects and absorption differences.
Solution Approach 2:
The patent modifies the chemical composition parameters of the photoresist system by incorporating specific copolymers with controlled glass transition temperatures and photoacid generator concentrations. These parameter changes optimize the diffusion and reaction characteristics to improve pattern distribution uniformity under EUV irradiation.
2Manufacturing precision
If conventional photoresist materials are used, then process simplicity is maintained, but pattern roughness and non-uniformity increase
Solution Approach 1:
The patent employs composite photoresist materials consisting of copolymer blends with specific functional units. These composite materials combine different polymer components with complementary properties to achieve superior pattern uniformity and reduced roughness while managing the increased compositional complexity.
3Manufacturing precision
If high energy EUV photons are used, then patterning capability is achieved, but energy per photon causes random irradiation regions and pattern deterioration
Solution Approach 1:
The patent converts the harmful high-energy photon shot noise into a beneficial effect by using the topcoat layer to absorb excess energy and generate photoacids. The photoacids then diffuse to provide controlled chemical amplification in the photoresist, transforming the random high-energy irradiation into a more uniform patterning 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 composition enhances pattern sensitivity and reduces energy consumption while minimizing pattern roughness and improving uniformity in EUV photoresist processes.
Implementation Method 1
a photoacid generator; wherein the photoacid generator is a non-ionic compound or an ionic compound... an amount of acid generated in the exposed region is increased
Implementation Method 2
EUV absorption difference between top and bottom of the photoresist... at least one selected from R3, L1, and L2 includes fluorine and a hydroxy group
Data Source
AI summary
Provided are a resist topcoat composition and a method of forming patterns using the resist topcoat composition, the resist topcoat composition including a copolymer including a first structural unit represented by Chemical Formula M-1 and a second structural unit represented by Chemical Formula M-2; a photoacid generator; and a solvent, wherein the photoacid generator is a non-ionic compound or an ionic compound, the non-ionic compound includes an organic sulfonate group, the ionic compound includes at least one selected from a conjugate base of an inorganic acid and a conjugate base of an organic sulfonic acid as an anion.