Acid-Decomposable Resist Composition for Semiconductor Pattern Formation
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Solution Overview
Problem
Current resist compositions for semiconductor production face challenges in achieving excellent sensitivity, resolving power, roughness characteristics, exposure latitude, and focus latitude, particularly when using ArF or EUV exposure apparatus with far-ultraviolet light sources.
Innovation Solution
A resist composition comprising an acid-decomposable resin that produces an alcoholic hydroxyl group upon acid exposure, enhancing its reactivity and polarity change, combined with an acid generator and other additives like surfactants and hydrophobic resins, to improve development performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional positive resist composition is used with alkali developer, then exposed areas are removed to obtain pattern, but it becomes extremely difficult to achieve excellent sensitivity, resolving power, roughness characteristics, exposure latitude, and focus latitude simultaneously
Solution Approach 1:
The patent inverts the conventional approach by using a positive resist composition that becomes insoluble in alkali developer after exposure and PEB, rather than soluble. The carboxyl groups formed during PEB create crosslinking that reduces solubility, causing exposed areas to remain while unexposed areas are removed during development, achieving negative pattern formation with superior comprehensive performance
Solution Approach 2:
The patent changes the solubility parameter of the resist composition through chemical modification. The carboxyl-containing polymer undergoes chemical transformation during PEB where carboxyl groups form crosslinks, fundamentally changing the solubility behavior from alkali-soluble to alkali-insoluble in exposed areas, enabling the inverted development mechanism
2Manufacturing precision
If wavelength of exposure light source is shortened to cope with miniaturization, then resolving power is enhanced, but sensitivity decreases due to light absorption
Solution Approach 1:
The patent performs preliminary chemical action during PEB by generating carboxyl groups through acid catalysis before development. This preliminary chemical transformation enhances the resist's response to short-wavelength exposure light, compensating for sensitivity loss while maintaining the resolving power gains from wavelength shortening
Solution Approach 2:
The patent substitutes the conventional photoacid generator mechanism with a carboxyl-containing polymer system that undergoes chemical transformation. The carboxyl groups provide both the acid catalytic function and the solubility modification function, replacing the need for separate chemical amplification components and improving sensitivity with short-wavelength light
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 superior sensitivity, resolving power, and reduced film thickness variation, while maintaining exposure latitude and focus latitude, thereby enhancing pattern formation quality in semiconductor manufacturing.
Implementation Method 1
first, a photoacid generator contained in exposed areas is decomposed by light irradiation to thereby generate an acid
Implementation Method 2
the generated acid exerts a catalytic action so that the alkali-insoluble group contained in the photosensitive composition is converted to an alkali-soluble group
Data Source
AI summary
Provided is a method of forming a pattern, ensuring excellent sensitivity, limiting resolving power, roughness characteristic, exposure latitude (EL), dependence on post-exposure bake (PEB) temperature and focus latitude (depth of focus DOF), and a resist composition for use in the method. The method comprises (A) forming a film from a resist composition comprising a resin containing a repeating unit containing a group that is decomposed when acted on by an acid to thereby produce an alcoholic hydroxyl group, which resin thus when acted on by an acid decreases its solubility in a developer containing an organic solvent, (B) exposing the film to light, and (C) developing the exposed film using a developer containing an organic solvent.