Resist Composition for Ultrafine Patterns via Acid Diffusion Control
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Solution Overview
Problem
Current pattern forming methods struggle to achieve excellent depth of focus for ultrafine patterns, particularly trench patterns with widths of 50 nm or less and hole patterns with diameters of 50 nm or less, due to challenges in exposing and resolving such fine regions.
Innovation Solution
A radiation-sensitive resin composition is developed, incorporating a basic compound with an alicyclic or heterocyclic structure and a resin that decomposes to generate a polar group, which enhances the depth of focus by controlling acid diffusion and solubility in developers, allowing for negative tone development using organic solvents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photoresist compositions are used for ultrafine pattern formation, then existing manufacturing processes can be maintained, but depth of focus is insufficient for trench patterns with width of 50 nm or less and hole patterns with diameter of 50 nm or less
Solution Approach 1:
The patent changes the chemical parameters of the photoresist composition by incorporating a basic compound with specific structural features (alicyclic or heterocyclic structure with basic site) and controlling the pKa of the conjugate acid to be between 1.0 and 6.0. This parameter optimization enables excellent depth of focus for ultrafine patterns while maintaining compatibility with existing lithographic processes
Solution Approach 2:
The patent creates a composite photoresist system by combining a basic compound with specific structural characteristics (alicyclic or heterocyclic with basic site) with a resin component that decomposes to generate polar groups. This composite material achieves superior depth of focus and pattern formation capability for ultrafine features
2Stability of the object's composition
If acid diffusion is increased to improve development uniformity, then development consistency is improved, but pattern resolution for ultrafine features deteriorates
Solution Approach 1:
The patent applies local quality control by using a basic compound with specific local structural characteristics (alicyclic or heterocyclic structure with basic site at specific position) that creates localized acid-base interactions. This local structural design enables controlled acid diffusion that maintains development uniformity while preserving pattern resolution for ultrafine features
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 improved depth of focus and pattern formation for ultrafine features by suppressing acid diffusion and optimizing reaction distribution, enabling the creation of precise trench and hole patterns with enhanced resolving power.
Implementation Method 1
a photoacid generator included in an exposed area first decomposes upon irradiation with light to generate an acid
Implementation Method 2
an alkali-insoluble group included in a photosensitive composition is changed into an alkali-soluble group by the catalytic action of the generated acid
Implementation Method 3
it has been desired to develop a resist composition having an excellent depth of focus... by suppressing acid diffusion and optimizing reaction distribution
Data Source
AI summary
An active-light-sensitive or radiation-sensitive resin composition includes a basic compound (A) corresponding to at least one of the following basic compound (A1) or (A2):(A1) a nonionic compound having an alicyclic structure (a1) and a basic site (b2) at a site different from the alicyclic structure within one molecule, or(A2) a nonionic compound having a heterocyclic structure (a2) having no basicity and a basic site (b2) at a site different from the heterocyclic structure within one molecule.