Positive Resist Composition for High-Resolution Lithography
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Solution Overview
Problem
Conventional chemically amplified resist materials face challenges in achieving high resolution for patterns of minute dimensions, particularly with exposure light sources having wavelengths shorter than 248 nm, due to inadequate transparency and molecular weight distribution issues.
Innovation Solution
A positive resist composition is developed, comprising a resin component with a core portion and arm portions obtained by anionic polymerization, which exhibits increased solubility in an alkali developing solution upon acid exposure, allowing for high-resolution pattern formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If PHS-based resins are used as base resin for KrF excimer laser lithography, then transparency to 248 nm light is improved, but resolution for wavelengths shorter than 248 nm deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the base resin from PHS-based (aromatic) to acrylic-based (aliphatic) resins. This parameter change maintains transparency for KrF excimer laser (248 nm) while improving resolution for shorter wavelengths (193 nm and below) by eliminating aromatic ring absorption
Solution Approach 2:
The patent uses composite acrylic resin systems combining multiple (meth)acrylate ester monomers with different properties. This composite approach optimizes both transparency across multiple wavelengths and resolution by balancing the characteristics of different resin components
2Ease of manufacture
If radical polymerization method is used to obtain base resin, then ease of manufacture is improved, but molecular weight distribution control deteriorates
Solution Approach 1:
The patent replaces radical polymerization with anionic polymerization method. This substitution provides better control over molecular weight distribution and polymer structure while maintaining manufacturing feasibility through well-established anionic polymerization techniques
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 enables the formation of resist patterns with improved resolution and shape fidelity, particularly effective for electron beam and EUV lithography, by controlling molecular weight distribution and solubility differences between exposed and unexposed regions.
Implementation Method 1
an acid-generator component (B) which generates acid upon irradiation
Implementation Method 2
a resin component (A) which exhibits increased solubility in an alkali developing solution under action of acid
Data Source
AI summary
The present invention provides a positive resist composition capable of forming a resist pattern with high resolution, and a method of forming a resist pattern.This composition is a positive resist composition including a resin component (A) which exhibits increased solubility in an alkali developing solution under action of acid, and an acid-generator component (B) which generates acid upon irradiation, the resin component (A) containing a polymer including: a core portion represented by general formula (1)[Chemical Formula 1]PX—Y)a (1)wherein P represents an a-valent organic group; a represents an integer of 2 to 20; Y represents an arylene group or an alkylene group of 1 to 12 carbon atoms; and X represents a specific linking group which can be cleaved under action of acid, and arm portions that are bonded to the core portion and are also composed of a polymer chain obtained by an anionic polymerization method.