Negative Resist Composition for High-Resolution EB Lithography
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Solution Overview
Problem
Chemically amplified negative resist compositions face challenges in achieving high resolution and low line edge roughness (LER) while minimizing temperature dependence and chemical flare issues, especially during high current quantity writing processes.
Innovation Solution
A negative resist composition incorporating a polymer with cyclic olefin units and acid-eliminable groups, combined with a carboxylic acid salt as a quencher, which reduces temperature dependence and enhances resolution and LER by mitigating the volatilization of acid-generated components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high current quantity writing is used to improve productivity, then writing speed increases, but temperature dependence and chemical flare increase causing resolution degradation
Solution Approach 1:
A quencher compound is introduced as an intermediary substance that absorbs excess acid generated during high current quantity electron beam writing. The quencher prevents acid diffusion and chemical flare to unexposed regions, thereby maintaining resolution and reducing temperature dependence even at high writing speeds
Solution Approach 2:
The patent converts the harmful effect of excess acid generation during high current writing into a beneficial process by using the quencher to locally neutralize acid in exposed regions. This prevents acid migration to unexposed areas and transforms the potential source of resolution degradation into a mechanism for maintaining pattern fidelity
2Productivity
If sensitivity is increased to improve productivity, then exposure efficiency increases, but resolution and line edge roughness deteriorate
Solution Approach 1:
The patent modifies the chemical parameters of the resist system by introducing a quencher with specific acid-base properties. This changes the acid diffusion dynamics and reaction kinetics, enabling high sensitivity exposure while maintaining sharp line edges and low roughness through controlled acid neutralization
3Speed
If temperature is increased to improve processing speed, then writing efficiency increases, but temperature dependence increases causing pattern size variation
Solution Approach 1:
The quencher provides a chemical feedback mechanism that compensates for temperature-induced variations in acid generation and diffusion. By neutralizing excess acid in a temperature-dependent manner, the quencher maintains consistent pattern dimensions across different processing temperatures and writing speeds
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 high resolution and minimal LER with reduced temperature dependence and suppressed chemical flare, effectively forming patterns with improved stability and accuracy during high current quantity writing.
Implementation Method 1
an acid generator which is decomposed to generate an acid upon exposure to radiation
Implementation Method 2
a basic compound for controlling diffusion of the acid generated upon exposure
Data Source
AI summary
A negative resist composition is provided comprising (A) a polymer comprising recurring units having an acid-eliminatable group and recurring units capable of generating acid upon exposure and (B) a carboxylic acid onium salt. When the negative resist composition is processed by the microprocessing technology, especially EB lithography, it forms a pattern having a very high resolution and minimal LER.