Ring-Opened Phthalic Anhydride Anti-Reflective Layer for 193nm Lithography
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Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in achieving ultrafine patterns with line widths of 0.10 micrometers or less due to reflection issues during lithographic processes, particularly with ArF excimer lasers, which require effective light absorption and high dry etching rates to prevent undercut and footing in semiconductor devices.
Innovation Solution
A novel light absorbent, represented by specific ring-opened phthalic anhydride compounds, is integrated into an organic anti-reflective layer composition, which includes a polymer, thermal acid generating agents, and crosslinking agents, to absorb reflected light and enhance etching rates, allowing for the formation of precise semiconductor patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional light absorbents are used in organic anti-reflective layers, then the layer can prevent reflection from underneath film layers, but the etching rate is insufficient and pattern profiles suffer from undercut and footing
Solution Approach 1:
The patent modifies the chemical structure of phthalic anhydride by ring-opening it to create compounds with specific functional groups (carboxylic acid groups) that enhance both light absorption at 193nm wavelength and reactivity with etching chemicals. This structural parameter change enables simultaneous improvement of pattern precision and etching rate
Solution Approach 2:
The patent creates a composite organic anti-reflective layer composition combining ring-opened phthalic anhydride derivatives with polymers and other additives. This composite material approach integrates multiple functions: light absorption, adhesion enhancement, and etching rate improvement, resolving the contradiction between pattern quality and processing speed
2Manufacturing precision
If the reflectance is reduced to less than 1% for uniform pattern formation, then pattern uniformity improves, but the complexity of achieving appropriate material composition increases
Solution Approach 1:
The ring-opened phthalic anhydride compounds serve multiple functions simultaneously: they act as light absorbents to reduce reflectance below 1%, provide adhesion promoters through their functional groups, and serve as etching rate enhancers. This multi-functionality simplifies the overall material system while achieving the required pattern uniformity
3Productivity
If ultrafine patterns with line widths of 0.10 micrometers or less are produced, then device integration increases, but reflection and stationary waves during lithographic processes worsen
Solution Approach 1:
The organic anti-reflective layer composed of ring-opened phthalic anhydride derivatives acts as an intermediary layer between the photoresist and the underlying film layers. This intermediary absorbs stray light and prevents stationary wave formation, enabling successful production of ultrafine patterns with 0.10 micrometer line widths or less
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 solution provides excellent adhesiveness, storage stability, and resolution in both C/H and L/S patterns, enabling the formation of high integration semiconductor devices with improved pattern profiles and rapid etching capabilities using a 193-nm light source.
Implementation Method 1
a novel light absorbent which can be used in an organic anti-reflective layer capable of absorbing reflected light that is generated during exposure in ultrafine patterning lithographic processes making use of 193-nm ArF excimer laser
Data Source
AI summary
A light absorbent for forming an organic anti-reflective layer, represented by the following formula 1 or formula 2, is provided:wherein A represents a substituted or unsubstituted, linear or branched, saturated tetravalent hydrocarbon group, a substituted or unsubstituted, linear or branched, saturated hydrocarbon group and containing one or more heteroatoms, a substituted or unsubstituted aromatic group, a substituted or unsubstituted heteroaromatic group, a substituted or unsubstituted alicyclic group, a substituted or unsubstituted heteroalicyclic group, a substituted or unsubstituted diaryl ether, a substituted or unsubstituted diaryl sulfide, a substituted or unsubstituted diaryl sulfoxide, a substituted or unsubstituted diaryl ketone, or a substituted or unsubstituted diaryl bisphenol A; R1, R2, and R3 each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted acetal group, or a substituted or unsubstituted hydroxyl group; and n is an integer from 2 to 500.