Resist Composition Stabilizing EUV Lithography Patterns
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Solution Overview
Problem
Current resist materials used in EUV and EB lithography face issues such as decreased contrast, thickness loss, and pattern roughening due to Out of Band (OoB) light and thermal instability during Post Exposure Bake (PEB), which affect the resolution and shape of resist patterns, particularly in DUV region exposure.
Innovation Solution
A resist composition containing a base component that generates acid upon exposure, featuring a copolymer with specific structural units including acid-decomposable groups, which increases polarity and changes solubility in developing solutions, reducing the impact of OoB light and thermal variations, thereby stabilizing pattern size and improving pattern shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional resist materials are used in EUV and EB lithography, then lithography process can be performed, but contrast decreases and thickness loss occurs due to OoB light
Solution Approach 1:
The patent modifies the chemical composition parameters of the resist material by incorporating specific acid-decomposable groups (carboxyl, hydroxyl, or amino groups) into the base resin structure. This changes the resist's interaction with OoB light and thermal energy, reducing harmful effects while maintaining lithography functionality. The specific functional groups alter the acid generation and decomposition characteristics, improving contrast and reducing thickness loss.
Solution Approach 2:
The patent creates a composite resist system combining a base resin with specific acid-decomposable functional groups and complementary acid-generator components. This composite structure enables the resist to simultaneously achieve high contrast, reduced OoB light sensitivity, and thermal stability during PEB, resolving the contradictions in pattern quality and harmful factor resistance.
2Manufacturing precision
If conventional resist materials are used, then exposure can be performed, but pattern roughening occurs due to thermal instability during PEB
Solution Approach 1:
The patent introduces specific acid-decomposable functional groups (carboxyl, hydroxyl, amino) into the base resin molecular structure, changing the thermal and chemical stability parameters. These groups decompose at controlled temperatures during PEB, generating acid that modifies the resin's solubility and prevents pattern roughening, while maintaining manufacturing precision.
Solution Approach 2:
The acid-decomposable functional groups act as intermediaries between thermal energy and the base resin structure. During PEB, these groups decompose to generate acid, which mediates the interaction between thermal stress and the resin, preventing direct thermal degradation that would cause pattern roughening.
3Reliability
If acid-generator component is added to base resin, then sensitivity to exposure light is improved, but solubility control in developing solution becomes more complex
Solution Approach 1:
The patent merges the base resin and acid-generator component into a single integrated resist composition where the acid-decomposable functional groups are incorporated directly into the base resin structure. This combining approach simplifies the overall composition structure while maintaining high sensitivity and improved lithography properties, as the acid generation and base resin functions are unified in one material system.
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 resist composition forms high-resolution patterns with improved shape stability and reduced sensitivity to PEB temperature, enhancing the contrast and thickness uniformity of resist patterns, particularly in EUV and EB lithography.
Implementation Method 1
a base component (A) which generates an acid upon exposure
Implementation Method 2
a structural unit (a11) containing an acid-decomposable group which exhibits increased polarity by the action of acid
Data Source
AI summary
A resist composition containing a base component (A) which generates an acid upon exposure and exhibits changed solubility in a developing solution by the action of acid, wherein the base component (A) contains a copolymer (A1) having a structural unit (a0) containing a group represented by the following general formula (a0-1) or (a0-2), a structural unit (a11) containing an acid-decomposable group which exhibits increased polarity by the action of acid and contains a polycyclic group, and a structural unit (a12) containing an acid-decomposable group which exhibits increased polarity by the action of acid and contains a monocyclic group. Each of the groups —R3—S+(R4)(R5) and Mm+ in the formula has only one aromatic ring as a whole or has no aromatic ring.